Black to move
17-year old Nyuima Tersee is new Nigerian Champion!
15 hours ago
30 December 2011
Friday Morning
In a three minute game, one must think fast. Having a rook for a knight is a clear advantage, but it can be a difficult endgame. Here I moved instantly, but Rybka required half of a minute to acknowledge that my move was best.
23 December 2011
And Again
Yesterday I posted two examples of recent success: "Checkmate with Pawns." Such checkmates are rare. However, it is worth mentioning that I will not be able to find one of those two games in my database, as I do not save bullet games. After posting, I found time for a few bullet games during a break from work, and for the third time this week, pulled off another such checkmate that will not make it to the database.
My move was the best, although Rybka requires some coaxing to acknowledge it. After 41.b7+ it is checkmate in nine. My opponent's choice ended things more rapidly, and prevented my need of a queen.
41...Kb8 42.Kb6 Be4 43.a7#.
White to move
My move was the best, although Rybka requires some coaxing to acknowledge it. After 41.b7+ it is checkmate in nine. My opponent's choice ended things more rapidly, and prevented my need of a queen.
41...Kb8 42.Kb6 Be4 43.a7#.
22 December 2011
Checkmate with Pawns
It has been nearly ten years since I was checkmated by two pawns in a complex and beautiful position on the Internet Chess Club. That game was the solitary example in my database of a rare and mostly theoretical possibility.
This week added two more. A Social Chess game that ended Tuesday had this finish.
49.b2 50.f6
Of course, he could have played 50.Ka2, leading to 50...Kc2, 51...b1Q and mate to follow.
50...Kb3 51.fxg7 a2#.
Yesterday, in a one-minute bullet game, I capped a series of games against my opponent with a nice victory. I won the series 9-4. In the finale, my opponent managed to shed a bishop in the early middle game, then two pawns.
Here we transition into a simple pawn endgame. When there are seconds remaining, it is important to reduce counterplay.
34...Rxb2 35.Rxb2 Bxb2+ 36.Kxb2 c5 37.Kc3 c4 38.Kd2 Kc5 39.Kc2 d4 40.Kb2 e4 41.Kc2 e3 42.Kd1 Kd5 43.Ke1 Ke4 44.a4 d3 45.a5 d2+
I would play 46.Ke2, if I were in my opponent's position. Perhaps he thought he might walk into stalemate, or perhaps with so little time left, he did not think about it.
46.Kd1 Kd3 47.a6 e2#.
This week added two more. A Social Chess game that ended Tuesday had this finish.
Black to move
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Of course, he could have played 50.Ka2, leading to 50...Kc2, 51...b1Q and mate to follow.
50...Kb3 51.fxg7 a2#.
Yesterday, in a one-minute bullet game, I capped a series of games against my opponent with a nice victory. I won the series 9-4. In the finale, my opponent managed to shed a bishop in the early middle game, then two pawns.
Black to move
Here we transition into a simple pawn endgame. When there are seconds remaining, it is important to reduce counterplay.
34...Rxb2 35.Rxb2 Bxb2+ 36.Kxb2 c5 37.Kc3 c4 38.Kd2 Kc5 39.Kc2 d4 40.Kb2 e4 41.Kc2 e3 42.Kd1 Kd5 43.Ke1 Ke4 44.a4 d3 45.a5 d2+
White to move
I would play 46.Ke2, if I were in my opponent's position. Perhaps he thought he might walk into stalemate, or perhaps with so little time left, he did not think about it.
46.Kd1 Kd3 47.a6 e2#.
16 December 2011
En Passant: History and Illustration
When chess was invented some 1500 years ago somewhere in India, or possibly China, pawns could move one square. As chess spread, a few variations on the rules developed. It is known from a manuscript that dates to 1283 that pawns could move two squares on the first move. Los Libros de Acedrez, Dados E Tablas was produced for Alfonso X of Castile (1221-1284), and describes the play of chess, dice, and backgammon.* According to James Murray, A History of Chess (1913), there were some conditions upon the pawn's double move. In any case, the en passant capture is not mentioned in the Alfonso MS. Two centuries later, however, the en passant capture is described (see Murray, 461).
We might conclude that the rule came into common practice some five centuries ago, roughly during the period when the queen acquired her powers. Our current rules regarding castling were still in flux in the late fifteenth century, and even in the sixteenth, so the en passant capture is not the newest rule change. Nevertheless, it remains the most difficult one for beginners to grasp.
I had a rare opportunity to execute an en passant capture yesterday. After two days of play and 24 moves, my opponent and I reached this position with him on move.
He played 25.c4, advancing a pawn two squares. The pawn passed over a square where it might have been captured by my d-pawn if it had moved one square.
The green arrow shows the path taken by the white pawn. The yellow arrow indicates the path the black pawn will take in order to capture en passant (in passing).
I played 25...dxc3.
After the en passant capture, the pawn on c4 has disappeared from the board. My pawn sits on c3. The tactical point of my capture was that now my rook is attacking the white queen: an en passant capture that creates a discovered attack. How often does something like that come up?
*A complete English translation and detailed analysis of Libros de Acedrez is available in the 2007 dissertation "Los libros de acedrex dados e tablas: Historical, Artistic and Metaphysical Dimensions of Alfonso X’s Book of Games" by Sonja Musser Golladay.
We might conclude that the rule came into common practice some five centuries ago, roughly during the period when the queen acquired her powers. Our current rules regarding castling were still in flux in the late fifteenth century, and even in the sixteenth, so the en passant capture is not the newest rule change. Nevertheless, it remains the most difficult one for beginners to grasp.
I had a rare opportunity to execute an en passant capture yesterday. After two days of play and 24 moves, my opponent and I reached this position with him on move.
White to move
He played 25.c4, advancing a pawn two squares. The pawn passed over a square where it might have been captured by my d-pawn if it had moved one square.
Black to move
The green arrow shows the path taken by the white pawn. The yellow arrow indicates the path the black pawn will take in order to capture en passant (in passing).
I played 25...dxc3.
White to move
After the en passant capture, the pawn on c4 has disappeared from the board. My pawn sits on c3. The tactical point of my capture was that now my rook is attacking the white queen: an en passant capture that creates a discovered attack. How often does something like that come up?
*A complete English translation and detailed analysis of Libros de Acedrez is available in the 2007 dissertation "Los libros de acedrex dados e tablas: Historical, Artistic and Metaphysical Dimensions of Alfonso X’s Book of Games" by Sonja Musser Golladay.
15 December 2011
Lesson of the Week
A holiday concert displaces one school chess club this week. Holiday distractions disrupt others. Last week's lesson on pins proved impossibly difficult for most of the young players in my clubs. Some were offered an easier lesson on pins last week: "While Looking at Pins." Another club saw the position from "While Looking at Pins" this week. Other groups this week are seeing the position below.
This position is problem number 1 is Fred Reinfeld, 1001 Winning Chess Sacrifices and Combinations (1955). This text is generally available for approximately $10. My copy is beginning to fall apart, and I may replace it. The principal difficulty young students would have in learning from it stems from descriptive notation. Algebraic is far simpler to master for the nine year old student, and is the notation system universally taught. Descriptive notation is worth learning because it provides access to many older texts, such as the exceptional checkmate manual, Georges Renaud and Victor Kahn, The Art of the Checkmate (1953). Reinfeld's text offers a one page explanation of descriptive notation in the front matter.
Reinfeld's text contains errors, but far fewer than will be evident in every book written by Bruce Pandolfini or by Eric Schiller. Reinfeld worked in an era before computers, checked his work carefully, and made a few errors in assessment. Pandolfini's work appears rushed into print without proper editing. Even so, I find that Pandolfini's Endgame Course (1988) is a highly instructive text for scholastic players. If I could give every child this text after his or her first tournament, and they could be induced to spend one hour per week studying it, skills would improve rapidly. Reinfeld's text is less elementary, focuses on middlegame tactics, rather than basic checkmates, and should be listed in every state qualifier's letter to Santa.
Reinfeld does not present his sources, but the position comes from Yanofsky -- Aitken, Hastings 1946. Yanofsky made the correct move and Aitken resigned.
White to move
This position is problem number 1 is Fred Reinfeld, 1001 Winning Chess Sacrifices and Combinations (1955). This text is generally available for approximately $10. My copy is beginning to fall apart, and I may replace it. The principal difficulty young students would have in learning from it stems from descriptive notation. Algebraic is far simpler to master for the nine year old student, and is the notation system universally taught. Descriptive notation is worth learning because it provides access to many older texts, such as the exceptional checkmate manual, Georges Renaud and Victor Kahn, The Art of the Checkmate (1953). Reinfeld's text offers a one page explanation of descriptive notation in the front matter.
Reinfeld's text contains errors, but far fewer than will be evident in every book written by Bruce Pandolfini or by Eric Schiller. Reinfeld worked in an era before computers, checked his work carefully, and made a few errors in assessment. Pandolfini's work appears rushed into print without proper editing. Even so, I find that Pandolfini's Endgame Course (1988) is a highly instructive text for scholastic players. If I could give every child this text after his or her first tournament, and they could be induced to spend one hour per week studying it, skills would improve rapidly. Reinfeld's text is less elementary, focuses on middlegame tactics, rather than basic checkmates, and should be listed in every state qualifier's letter to Santa.
Reinfeld does not present his sources, but the position comes from Yanofsky -- Aitken, Hastings 1946. Yanofsky made the correct move and Aitken resigned.
13 December 2011
Improving Tactics: Training Resources
At the present time, in any given week, I use the Tactics Trainer at Chess.com (more than 32 hours since joining the site), the problems in the Shredder iPad app, my pawn endgame flash cards, or one of several books.
Ten years ago, I spent 15-30 minutes nearly every morning for several months working through problems in Laszlo Polgar, Chess Training in 5334 Positions (1994), which is pictured at the bottom of a stack in the image. Polgar's book, which may have been assembled by his daughter Susan, consists mostly of checkmate problems. This collection draws from an extensive library of composed problems, and a smaller collection of positions from actual play. The effectiveness of the training stems from repetition of patterns. Problems 1-306 are checkmate in one; 307-3718 are mate in two; 3719-4462 are mate in three. I completed a bit more than the first 1500 problems.
The book also contains 600 miniature games, a bit more than 100 simple endgames, and more than 100 combinations from the Polgar sisters' games. Occasionally, this book shows up on sale tables for $10, which strikes me as an opportunity calling for action.
Art of the Checkmate
While Polgar's Chess teaches checkmate patterns through compositions and miniatures, Georges Renaud and Victor Kahn, The Art of the Checkmate (1953) employs real games. The organization of this classic text, and the quality of instruction it offers, are vastly superior to Murray Chandler, How to Beat Your Dad at Chess (1998). However, Chandler's book uses algebraic notation, while Renaud and Kahn is available only in descriptive. Other books with guides to basic checkmate patterns include Fred Reinfeld, How to Force Checkmate (1947); V. Vukovic, The Art of Attack in Chess (1965); and Jonathan Tisdall, Improve Your Chess Now (1997). My effort to extend the work naming, classifying, and organizing basic patterns by the authors of several of these texts resulted in a self-published pamphlet that I use in teaching, "Checklist of Checkmates: With Exercises" (2007). My pamphlet (pictured above) identifies 34 basic patterns sorted into six groups to aid learning, and offers 139 problems all from actual play. My study of The Art of the Checkmate, and the other books, followed by extensive database research to find examples in play, has done wonders for the development of my skill.
Basic Tactical Motifs
My library contains several terrific workbooks designed especially for youth who are beginning to intermediate players. These workbooks vary in method and content, but all stress basic tactical motifs--discovery, pins, skewers, removing the guard, etc.--through repetition. John A. Bain, Chess Tactics For Students (1993) uses fill-in-blank worksheets with clear diagrams. Chapter one offers 30 problems involving pins. Subsequent chapters are "Back Rank Combinations," "Knight Forks," "Other Forks/Double Attacks," and ten more chapters. After completing this workbook, young players might advance to Al Woolum, The Chess Tactics Workbook, 4th edition (2000); Todd Bardwick, Chess Workbook for Children (2006); or Dean Ippolito, Chess Tactics for Scholastic Players (2006). Each of these other three offer problems more challenging than Bain's, but also include very simple problems in the beginning. Those sensitive to patronizing language towards women and girls may find the prose in Bardwick's text distracting, but it offers good quality instruction otherwise.
While my chess students and their parents gain access to an abundance of free and inexpensive resources that I churn out as teaching materials, the research process improves my skills, too. When I am not solving problems, I am looking for problems to put in front of beginning players. Sometimes, these are more challenging than expected, as last week's lesson on pins proved to have been.
Tactics for Advanced Players
Prior to the explosion of youth chess, a standard beginning text was Fred Reinfeld, 1001 Winning Chess Sacrifices and Combinations (1955). It is organized by theme with dozens of problems in each chapter. Generations of masters have started with this book. Reinfeld wrote a few other 1001 texts, but this one seems most widely available. In "Where the Rubber Meet the Road," I detailed my training method with this text and a chess playing engine. Beyond finding Reinfeld's idea, I labor to convert the advantage gained through the tactic. I have not employed this training method in 2011, but expect to return to such training for part of 2012.
Lev Alburt, Chess Training Pocket Book (1997) contains 300 positions, four to a page. The solutions are on the facing page, making self-discipline a necessary feature of using the text for training. These well-chosen 300 positions, most from practical play, include common tactical motifs, positional concepts, and endgame fundamentals. Over the course of several years, I went through the entire book both randomly and in sequence at least twice, and have also used the book as a reference when compiling lessons for others. This book spent several years on my bedside table. The book indexes the problems by themes and by players. Alburt, Chess Training Pocket Book II (2008) offers 320 new positions in the same format. This book will be a central component of my training in the near future. With such collections, I think it is best to go through all the problems, and then several months or a year later, go through them again.
Most club players should be able to solve the problems in Alburt's books in no more than a few minutes each, and errors will be easily corrected. A few times through these books should leave the student with a core knowledge of important positions. For more challenging tactical exercises, I turn to John Nunn's Chess Puzzle Book (1999) and Paata Gaprindashvili, Imagination in Chess: How to Think Creatively and Avoid Foolish Mistakes (2004). Both of these texts offer fresh positions. That is, the positions in these texts will not be found in Reinfeld. Some of those in Alburt's texts are in Reinfeld, as well as in dozens of other training texts. Alburt's books lay the foundation that helped me reach USCF Class A, and to secure my position there. As I struggle to move up to Expert Class, and possibly master, Nunn's and Gaprindashvili's texts offer resources of value. Imagination in Chess also offers suggestions for effective thought processes. Gaprindashvili's logical process may be considered an improvement over the famed analysis tree in Alexander Kotov's Think Like a Grandmaster (1971). Readers may differ in their assessments of these modes of systematic thinking.
Two other challenging texts offer exceptional insight into the nature of chess tactics, and plenty of training material. These are not collections of problems so much as treatises on the the middlegame. Yuri Averbakh, Chess Tactics for Advanced Players (1992) seeks to build a theoretical base for comprehension of chess tactics. Mark Dvoretsky, Secrets of Chess Tactics (1992) takes a more practical approach, but also contains much of theoretical value. The positions analyzed in both texts can be quite challenging, even for masters.
08 December 2011
While Looking at Pins
The critical moment when I gained a clear advantage in my last completed ChessWorld correspondence game presents another illustration of using a pin. I attacked the rook on c8 by moving my bishop to a6. Instead of shuffling the rook to a safer square on the eighth rank, my opponent moved it to c7. Now, the pin on the knight nets me a piece for a pawn.
18.d5!
Elementary. Pile on the pinned piece. Moving the knight loses the rook, and so 18...exd5 19.exd5 Qd6 20.dxc6+-.
White to move
18.d5!
Elementary. Pile on the pinned piece. Moving the knight loses the rook, and so 18...exd5 19.exd5 Qd6 20.dxc6+-.
07 December 2011
Problems of the Week
Working with pins
Although these four problems seem rather elementary to me, the second graders found them challenging yesterday. Today, I'll give them to some middle school students in a chess class for home school students, and to an after school chess club at another elementary school. The older students where the second graders had trouble get their crack on Thursday. On Saturday, players from these schools, as well as others, meet in a youth tournament. Perhaps some of them will do more with pins this weekend.
My procedure this week is a bit different than the norm. Usually, I have one problem on the demonstration board. The entire club gathers to discuss the position, which can mean as many as thirty young players suggesting the first move that looks right. This week, I printed sheets with all four problems, and the players work in teams trying to solve all four before another team does so. I asked the five strongest second graders on Tuesday to each work with a first grader or kindergartner as a teammate. With an abundance of help from me, including using the demo board to give everyone answers to the first two, one second grader finally had four correct answers written on his sheet.
A key concept for working with pins is piling on. This technique is particularly apparent, it seems to me, in the second problem. All of these problems exploit the vulnerability of a king.
Although these four problems seem rather elementary to me, the second graders found them challenging yesterday. Today, I'll give them to some middle school students in a chess class for home school students, and to an after school chess club at another elementary school. The older students where the second graders had trouble get their crack on Thursday. On Saturday, players from these schools, as well as others, meet in a youth tournament. Perhaps some of them will do more with pins this weekend.
My procedure this week is a bit different than the norm. Usually, I have one problem on the demonstration board. The entire club gathers to discuss the position, which can mean as many as thirty young players suggesting the first move that looks right. This week, I printed sheets with all four problems, and the players work in teams trying to solve all four before another team does so. I asked the five strongest second graders on Tuesday to each work with a first grader or kindergartner as a teammate. With an abundance of help from me, including using the demo board to give everyone answers to the first two, one second grader finally had four correct answers written on his sheet.
White to move
Black to move
White to move
White to move
A key concept for working with pins is piling on. This technique is particularly apparent, it seems to me, in the second problem. All of these problems exploit the vulnerability of a king.
02 December 2011
Pin is Opportunity for Discovery
Chess Informant 105/75 was Vasily Ivanchuk's win over Sergey Karjakin at the 2009 Corus Chess Tournament at Wijk aan Zee in the Netherlands. At a critical point in the game, Ivanchuk sacrificed a pawn to gain the bishop pair and provoke a sequence of exchanges. I blogged this game while it was in progress ("Wijk aan Zee: Round Eight") and then took another look through Informant's annotations this morning. The game placed third in the voting for the best of Informant 105.
After the pawn sacrifice, I wrote, "Ivanchuk appears to have compensation for the pawn, but no significant advantage." Looking through the game this morning, I reached a different conclusion. Karjakin's gain of a pawn left his pawn structure in a mess. All his queenside pawns became weak. Although the a- and c-pawns are not technically isolated because the b-pawn remains on the board, they are too far advanced to receive assistance from the backwards b-pawn. Moreover, White's bishops control all the key squares. Over the course of the game, Ivanchuk's bishop pair mopped up Karjakin's weakened pawns. Eventually, Ivanchuk was the one with an extra pawn and was ready to go two pawns ahead when Karjakin threw in the towel. Karjakin went on to win the tournament with five wins, six draws, and two losses; Ivanchuk finished in a share of last place.
On the other hand, my engine finds the position equal after Ivanchuk's sacrifice.
The annual tournament in Wijk aan Zee was begun as a local event in 1938 by the Hoogoven Chess Club, consisting of workers at the steelworks. In 1939 it attracted national attention, and then in subsequent years gained international attention. It has grown into one of the major annual Grandmaster tournaments and a chess festival for all levels of players. As the local steel factory has changed ownership, so has the name of the tournament. In 2007, India's Tata Steel purchased Corus, and so beginning with the 2011 Wijk aan Zee event, it is now called the Tata Steel Chess Tournament. One of the first chess books that I purchased and studied regularly was Wijk aan Zee: Grandmaster Chess Tournament 1975 (1976). This old paperback is showing its age from many years of use, but remains a treasured possession.
White's pawn on b4 is pinned to the queen by Black's bishop on e7. However, the bishop is undefended and b4-b5 attacks the Black queen. Thus, the pinned pawn's advance creates a discovered attack on the bishop, and Black has no choice better than exchanging bishop for knight.
23...axb5 24.Qxe7 bxa4 25.Rd1 Nf8 26.Rd6 Re8 27.Rxc6 Rxe7 28.Bc5
Houdini sees a difference of just under half a pawn between the move Karjakin played here and the optimum choice. The Chess Informant annotations provided by Ivanchuk and the lines suggested by Houdini both favor 28...Re8. This move has the idea of swapping rooks before other material comes off.
Karjakin played 28...Rd7. He was under considerable time pressure, having thought long before playing 22...f5.
29.Rb6 fxe4 30.fxe4 c3 31.Kf2 Ba2 32.a6 bxa6
Black is temporarily ahead by two pawns, but positionally, White has a clear advantage.
33.Rb8 Rf7+ 34.Ke3 g6 35.Bd6 Rf6 36.Rd8
Karjakin is not in zugzwang, but almost. There is nothing useful that he can do. I revised my analysis of the position after Ivanchuk's pawn sacrifice because even with optimum play, there is little that Black can do other than watch White build up his attack against the weakened pawns. With the rooks off the board, perhaps the technique would have required more skill. It seems to me that this sort of position merits one of those comments, "the rest is a matter of technique." Such comments seem lazy, of course, and are spurned by chess readers. For a super-grandmaster like Vasily Ivanchuk, such technique has been honed through extensive preparation, lots of playing experience, and keen instincts. For the rest of us, such technique requires that we continue to learn. Even so, White's plan is simple and straightforward: mop up the pawns and turn the remainder of the endgame into one where White has more.
When it is clear that White has more pawns, Black can resign in a grandmaster game. Among class players, resignation is deferred until the pawn promotes. Among young scholastic players, checkmate must be the finish.
36...a3 37.Bxa3 Kg7 38.Bd6 Rf7 39.Bxe5+ Kh6 40.Bxa6 Ne6 41.Rc8
Karjakin resigned in this position. Another time to resign for a grandmaster is after reaching the time control. Karjakin played a lot of moves in a hurry. Now, with time to consider his position, he sees clearly that he is sunk.
After the pawn sacrifice, I wrote, "Ivanchuk appears to have compensation for the pawn, but no significant advantage." Looking through the game this morning, I reached a different conclusion. Karjakin's gain of a pawn left his pawn structure in a mess. All his queenside pawns became weak. Although the a- and c-pawns are not technically isolated because the b-pawn remains on the board, they are too far advanced to receive assistance from the backwards b-pawn. Moreover, White's bishops control all the key squares. Over the course of the game, Ivanchuk's bishop pair mopped up Karjakin's weakened pawns. Eventually, Ivanchuk was the one with an extra pawn and was ready to go two pawns ahead when Karjakin threw in the towel. Karjakin went on to win the tournament with five wins, six draws, and two losses; Ivanchuk finished in a share of last place.
On the other hand, my engine finds the position equal after Ivanchuk's sacrifice.
The annual tournament in Wijk aan Zee was begun as a local event in 1938 by the Hoogoven Chess Club, consisting of workers at the steelworks. In 1939 it attracted national attention, and then in subsequent years gained international attention. It has grown into one of the major annual Grandmaster tournaments and a chess festival for all levels of players. As the local steel factory has changed ownership, so has the name of the tournament. In 2007, India's Tata Steel purchased Corus, and so beginning with the 2011 Wijk aan Zee event, it is now called the Tata Steel Chess Tournament. One of the first chess books that I purchased and studied regularly was Wijk aan Zee: Grandmaster Chess Tournament 1975 (1976). This old paperback is showing its age from many years of use, but remains a treasured possession.
White to move
White's pawn on b4 is pinned to the queen by Black's bishop on e7. However, the bishop is undefended and b4-b5 attacks the Black queen. Thus, the pinned pawn's advance creates a discovered attack on the bishop, and Black has no choice better than exchanging bishop for knight.
23...axb5 24.Qxe7 bxa4 25.Rd1 Nf8 26.Rd6 Re8 27.Rxc6 Rxe7 28.Bc5
Black to move
Houdini sees a difference of just under half a pawn between the move Karjakin played here and the optimum choice. The Chess Informant annotations provided by Ivanchuk and the lines suggested by Houdini both favor 28...Re8. This move has the idea of swapping rooks before other material comes off.
Karjakin played 28...Rd7. He was under considerable time pressure, having thought long before playing 22...f5.
29.Rb6 fxe4 30.fxe4 c3 31.Kf2 Ba2 32.a6 bxa6
White to move
Black is temporarily ahead by two pawns, but positionally, White has a clear advantage.
33.Rb8 Rf7+ 34.Ke3 g6 35.Bd6 Rf6 36.Rd8
Black to move
Karjakin is not in zugzwang, but almost. There is nothing useful that he can do. I revised my analysis of the position after Ivanchuk's pawn sacrifice because even with optimum play, there is little that Black can do other than watch White build up his attack against the weakened pawns. With the rooks off the board, perhaps the technique would have required more skill. It seems to me that this sort of position merits one of those comments, "the rest is a matter of technique." Such comments seem lazy, of course, and are spurned by chess readers. For a super-grandmaster like Vasily Ivanchuk, such technique has been honed through extensive preparation, lots of playing experience, and keen instincts. For the rest of us, such technique requires that we continue to learn. Even so, White's plan is simple and straightforward: mop up the pawns and turn the remainder of the endgame into one where White has more.
When it is clear that White has more pawns, Black can resign in a grandmaster game. Among class players, resignation is deferred until the pawn promotes. Among young scholastic players, checkmate must be the finish.
36...a3 37.Bxa3 Kg7 38.Bd6 Rf7 39.Bxe5+ Kh6 40.Bxa6 Ne6 41.Rc8
Black to move
Karjakin resigned in this position. Another time to resign for a grandmaster is after reaching the time control. Karjakin played a lot of moves in a hurry. Now, with time to consider his position, he sees clearly that he is sunk.
30 November 2011
Latent Tactics
Lesson of the Week
A jury of Grandmasters votes on the best games of each issue of Chess Informant. For Informant 105 (2009), Topalov -- Kamsky, a rapid game played in Nice, France, placed second. This win with Black by Kamsky demonstrates how a queen and knights can exploit disharmony among the enemy forces. My lesson for young chess players this week, however, is more elementary: simple tactics latent in a complex position.
Topalov still had chances to gain an advantage from the position after Black's fourteenth move.
The game was annotated for Informant by Sergei Shipov. He marked Topalov's move, 15.b4, as dubious. According to Shipov, White would have had a slight advantage after 15.Be3. I ran some engines on the position and learned that Be3 is Rybka's second choice and Houdini's first. Rybka's top choice is also the choice of Stockfish: 15.Qa2.
The second choice of Stockfish was the first move that I considered, and it, too, is covered in Shipov's annotations. In the variation that he gives are some instructive tactics suitable for elementary players.
15.Nxb7 (variation given by Shipov, Informant 105/48)
It often seems sensible to exchange a knight for a bishop, and in this case it clears the way for the win of a pawn, or so it seems after shallow analysis. But, deeper into the line, we see that White does not retain the extra pawn and comes under an attack that demonstrates the advantage has shifted to Black.
15...Qxb7 16.Qxa6?! Shipov marks this move as dubious, although it is the logical idea behind 15.Nxb7.
16...Qxa6 17.Rxa6 Nc5
The Black knight forks pawn, bishop, and rook. As either the bishop or rook must succumb, the logical move is to attack Black's undefended bishop.
18.Ra7 Bd8!
In Shipov's line, Black keeps the bishops on the board. Frequently, maintaining a bishop pair is an advantage in top-level chess, but Black's knights are the powerful pieces in this position, just as they were in the actual game. In this variation, Black's dark-squared bishop also has come to life.
19.Bc2 Bb6
Shipov's variation ends here with the assessment that Black has a slight advantage and an attack, although still one pawn down.
Even beginning players should be able to see that 19...Bb6 attacks the rook, and that after it moves to safety, the bishop checks the White monarch as soon as the Knight on c5 moves. Play might continue 20.Ra1 Nxe4+ 21.Kh1 Nxc3 22.bxc3. Black has regained the pawn and shackled White with doubled pawns on the c-file. Part of the idea behind 15.Nxb7 was to create a passed b-pawn, but that idea failed.
A jury of Grandmasters votes on the best games of each issue of Chess Informant. For Informant 105 (2009), Topalov -- Kamsky, a rapid game played in Nice, France, placed second. This win with Black by Kamsky demonstrates how a queen and knights can exploit disharmony among the enemy forces. My lesson for young chess players this week, however, is more elementary: simple tactics latent in a complex position.
Topalov still had chances to gain an advantage from the position after Black's fourteenth move.
White to move
The game was annotated for Informant by Sergei Shipov. He marked Topalov's move, 15.b4, as dubious. According to Shipov, White would have had a slight advantage after 15.Be3. I ran some engines on the position and learned that Be3 is Rybka's second choice and Houdini's first. Rybka's top choice is also the choice of Stockfish: 15.Qa2.
The second choice of Stockfish was the first move that I considered, and it, too, is covered in Shipov's annotations. In the variation that he gives are some instructive tactics suitable for elementary players.
15.Nxb7 (variation given by Shipov, Informant 105/48)
It often seems sensible to exchange a knight for a bishop, and in this case it clears the way for the win of a pawn, or so it seems after shallow analysis. But, deeper into the line, we see that White does not retain the extra pawn and comes under an attack that demonstrates the advantage has shifted to Black.
15...Qxb7 16.Qxa6?! Shipov marks this move as dubious, although it is the logical idea behind 15.Nxb7.
16...Qxa6 17.Rxa6 Nc5
The Black knight forks pawn, bishop, and rook. As either the bishop or rook must succumb, the logical move is to attack Black's undefended bishop.
White to move
18.Ra7 Bd8!
In Shipov's line, Black keeps the bishops on the board. Frequently, maintaining a bishop pair is an advantage in top-level chess, but Black's knights are the powerful pieces in this position, just as they were in the actual game. In this variation, Black's dark-squared bishop also has come to life.
19.Bc2 Bb6
Shipov's variation ends here with the assessment that Black has a slight advantage and an attack, although still one pawn down.
White to move
Even beginning players should be able to see that 19...Bb6 attacks the rook, and that after it moves to safety, the bishop checks the White monarch as soon as the Knight on c5 moves. Play might continue 20.Ra1 Nxe4+ 21.Kh1 Nxc3 22.bxc3. Black has regained the pawn and shackled White with doubled pawns on the c-file. Part of the idea behind 15.Nxb7 was to create a passed b-pawn, but that idea failed.
20 November 2011
Press the Attack
This afternoon, in a make-up game for the Turkey Quads, I had White in this position.
How should White press the attack?
White to move
How should White press the attack?
19 November 2011
Choose your Endgame
When a player is ahead by a pawn, which is more favorable: rook versus rook or same color bishops?
In the Turkey Quads on Thursday night, my opponent faced this choice.
I expected 52.Ra8 Ra2+ 53.Kg3 Bc4 54.Rxa2 Bxa2, and then I must defend a position where his bishop is the wrong color for the h-pawn, but the e-pawn represents a significant threat.
My opponent opted to exchange bishops. 52.Bxa6 Rxa6, and I was left defending with the rook. Having spent a fair amount of time last spring studying some of Vasily Smyslov's rook endgames, I played with some confidence that I could find the correct moves and hold the position.
See "Rook Endgame: Critical Position," "Play like Smyslov," and "The Active Rook."
Did my opponent make the wrong choice on move 52? Did he have better chances in a bishop endgame? I think so, but am not certain. Chess engines are not particularly helpful evaluating such positions as they may give +2.50 in positions that are theoretical draws.
In the Turkey Quads on Thursday night, my opponent faced this choice.
White to move
I expected 52.Ra8 Ra2+ 53.Kg3 Bc4 54.Rxa2 Bxa2, and then I must defend a position where his bishop is the wrong color for the h-pawn, but the e-pawn represents a significant threat.
White to move
My opponent opted to exchange bishops. 52.Bxa6 Rxa6, and I was left defending with the rook. Having spent a fair amount of time last spring studying some of Vasily Smyslov's rook endgames, I played with some confidence that I could find the correct moves and hold the position.
See "Rook Endgame: Critical Position," "Play like Smyslov," and "The Active Rook."
White to move
Did my opponent make the wrong choice on move 52? Did he have better chances in a bishop endgame? I think so, but am not certain. Chess engines are not particularly helpful evaluating such positions as they may give +2.50 in positions that are theoretical draws.
15 November 2011
Lesson of the Week
The Games of Gioachino Greco
Gioachino Greco recorded a number of games in his chess notebooks beginning as early as 1619. As he traveled from his native Italy to France and England, he sold copies of these games to patrons who sought chess instruction from him. These games are some of the oldest recorded complete games of chess available. They offer many useful lessons in chess tactics.
This week, we are highlighting a few key positions from two of these games.
In addition to tactics, principally discovery, students should learn to examine king safety and material imbalance while studying these positions.
The Games
Here are the game scores from which these positions arose. Both games are identical until White's tenth move.
NN - Greco,Gioacchino [C50]
Europe 1620
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.0–0 Nf6 5.Re1 0–0 6.c3 Re8 7.d4 exd4 8.e5 Ng4 9.Bg5 Nxf2 10.Qb3 dxc3 11.Bxd8 cxb2 12.Nc3 Nd1+ 13.Kf1 bxa1Q 14.Rxd1 Qxd1+ 15.Nxd1 Nxd8 0–1
NN - Greco,Gioacchino [C50]
Europe 1620
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.0–0 Nf6 5.Re1 0–0 6.c3 Re8 7.d4 exd4 8.e5 Ng4 9.Bg5 Nxf2 10.Bxd8 Nxd1 11.Rxd1 dxc3+ 12.Kf1 cxb2 13.Nbd2 bxa1Q 14.Rxa1 Nxd8 0–1
Gioachino Greco recorded a number of games in his chess notebooks beginning as early as 1619. As he traveled from his native Italy to France and England, he sold copies of these games to patrons who sought chess instruction from him. These games are some of the oldest recorded complete games of chess available. They offer many useful lessons in chess tactics.
This week, we are highlighting a few key positions from two of these games.
Black to move
Black to move
Black to move
In addition to tactics, principally discovery, students should learn to examine king safety and material imbalance while studying these positions.
The Games
Here are the game scores from which these positions arose. Both games are identical until White's tenth move.
NN - Greco,Gioacchino [C50]
Europe 1620
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.0–0 Nf6 5.Re1 0–0 6.c3 Re8 7.d4 exd4 8.e5 Ng4 9.Bg5 Nxf2 10.Qb3 dxc3 11.Bxd8 cxb2 12.Nc3 Nd1+ 13.Kf1 bxa1Q 14.Rxd1 Qxd1+ 15.Nxd1 Nxd8 0–1
NN - Greco,Gioacchino [C50]
Europe 1620
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.0–0 Nf6 5.Re1 0–0 6.c3 Re8 7.d4 exd4 8.e5 Ng4 9.Bg5 Nxf2 10.Bxd8 Nxd1 11.Rxd1 dxc3+ 12.Kf1 cxb2 13.Nbd2 bxa1Q 14.Rxa1 Nxd8 0–1
11 November 2011
Castling Queenside in the Queen's Gambit
I won my game in the Turkey Quads last night, but I was not happy with my opening. It seemed to me that Black too easily gained equality, and perhaps even had chances for the advantage. My opponent missed these chances, but lingering doubts concerning my play through the first ten moves or so haunt me. Hence, I was digging into the Encyclopedia of Chess Openings when I found a curiosity: 10.O-O-O.
A search of Chess Informants 1-103 (I need to buy the past two year's issues to bring my collection up to date) turns up two games, both embedded into ECO: Ree - Pfleger 1966 Informant 1/366, and Ftacnik - Zaw 2000 Informant 80/465. Searching the larger databases in ChessBase 11 produces more games, earlier games, and the information that GM Ľubomír Ftáčnik is the "strongest player" who has employed this line. Perhaps Akiba Rubinstein was stronger, but he played prior to FIDE adopting an Elo rating system, and so CB 11 ignores his efforts in the data field reporting "strongest". Alexander Alekhine played it once in a simul, as well, but he lost. Boris Spassky reached a similar position after 8.O-O-O, and the line appears in ECO (Informant 2/507).
ChessBase Online contains forty-seven games with the position from ECO in the image above. White scores a shocking 70.2% in these games. Of course, some of these games in the database are between relatively weak players. Most are interesting games between masters.
White's plan is not difficult to fathom: an all-out assault on the enemy king. Black must seek counterplay that exploits the half-open c-file. White's attack is already better prepared, so Black's task is difficult. There were eleven games 1905-1966 with ten White wins and Alekhine's loss. The first draw occurred in 1971.
Black's most popular replies are 10...Ne4 and 10...c5, but Win Lay Zaw's 10...Re8 deserves scrutiny. Zaw was not the first to play this move, which appears one other time in the ChessBase database. Zaw's novelty came on the next move, 11...Nf8. In the Informant annotations, Ftacnik points out a draw that Zaw missed near the end. Zaw's pawns nearly rolled over the top of White's position down the center.
I am looking through these games, which offer some interesting study material featuring attack and counter-attack.
A search of Chess Informants 1-103 (I need to buy the past two year's issues to bring my collection up to date) turns up two games, both embedded into ECO: Ree - Pfleger 1966 Informant 1/366, and Ftacnik - Zaw 2000 Informant 80/465. Searching the larger databases in ChessBase 11 produces more games, earlier games, and the information that GM Ľubomír Ftáčnik is the "strongest player" who has employed this line. Perhaps Akiba Rubinstein was stronger, but he played prior to FIDE adopting an Elo rating system, and so CB 11 ignores his efforts in the data field reporting "strongest". Alexander Alekhine played it once in a simul, as well, but he lost. Boris Spassky reached a similar position after 8.O-O-O, and the line appears in ECO (Informant 2/507).
ChessBase Online contains forty-seven games with the position from ECO in the image above. White scores a shocking 70.2% in these games. Of course, some of these games in the database are between relatively weak players. Most are interesting games between masters.
White's plan is not difficult to fathom: an all-out assault on the enemy king. Black must seek counterplay that exploits the half-open c-file. White's attack is already better prepared, so Black's task is difficult. There were eleven games 1905-1966 with ten White wins and Alekhine's loss. The first draw occurred in 1971.
Black's most popular replies are 10...Ne4 and 10...c5, but Win Lay Zaw's 10...Re8 deserves scrutiny. Zaw was not the first to play this move, which appears one other time in the ChessBase database. Zaw's novelty came on the next move, 11...Nf8. In the Informant annotations, Ftacnik points out a draw that Zaw missed near the end. Zaw's pawns nearly rolled over the top of White's position down the center.
I am looking through these games, which offer some interesting study material featuring attack and counter-attack.
09 November 2011
Learning from Greco
Gioacchino Greco was a chess teacher four centuries ago. The small selection of his games, likely created as lessons rather than a record of actual games, serve as a useful primer in chess tactics. The ChessBase online database contains eighty-three such games, including quite possibly the first smother mate.
These games can be accessed via the ChessBase iPad app, and of course through any of several ChessBase programs. While ChessBase 11 offers the quickest access, and the easiest structure for saving, analyzing, and recording comments, the iPad app offers quick access from anywhere the user has a connection.
NN - Greco,Gioacchino [C30]
Europe, 1620
1.e4 e5 2.f4 f5 3.exf5 Qh4+ 4.g3 Qe7 5.Qh5+ Kd8 6.fxe5 Qxe5+ 7.Be2 Nf6 8.Qf3 d5
This position appears to me to be the first of several critical positions. I do not like 9.g4, Greco's move, and would favor moving the d-pawn forward. No analysis engine is available within the Chessbase app, forcing me to rely upon my own resources. I like 9.d3 to bring the dark-squared bishop into play, and perhaps find security for the king by castling that direction.
By calling up Greco's games in ChessBase 11, I was able in less than five minutes to create a PGN database of his games in my Dropbox folder, and then open this database in tChessPro, another iPad app. That app has a built in chess engine.
The tChess Pro engine likes Greco's move better than I do, but agrees with my assessment that after 9.g4 h5, White should thrust the g-pawn another square forward. For the record, Rybka 4 prefers 9.d4.
9.g4 h5 10.h3 hxg4 11.hxg4 Rxh1 12.Qxh1 Qg3+ 13.Kd1 Nxg4 14.Qxd5+ Bd7 15.Nf3
White's play offers a series of instructive inaccuracies. After this final error, checkmate is forced.
15...Nf2+ 16.Ke1 Nd3+ 17.Kd1 Qe1+ 18.Nxe1 Nf2# 0–1
These games can be accessed via the ChessBase iPad app, and of course through any of several ChessBase programs. While ChessBase 11 offers the quickest access, and the easiest structure for saving, analyzing, and recording comments, the iPad app offers quick access from anywhere the user has a connection.
NN - Greco,Gioacchino [C30]
Europe, 1620
1.e4 e5 2.f4 f5 3.exf5 Qh4+ 4.g3 Qe7 5.Qh5+ Kd8 6.fxe5 Qxe5+ 7.Be2 Nf6 8.Qf3 d5
This position appears to me to be the first of several critical positions. I do not like 9.g4, Greco's move, and would favor moving the d-pawn forward. No analysis engine is available within the Chessbase app, forcing me to rely upon my own resources. I like 9.d3 to bring the dark-squared bishop into play, and perhaps find security for the king by castling that direction.
By calling up Greco's games in ChessBase 11, I was able in less than five minutes to create a PGN database of his games in my Dropbox folder, and then open this database in tChessPro, another iPad app. That app has a built in chess engine.
The tChess Pro engine likes Greco's move better than I do, but agrees with my assessment that after 9.g4 h5, White should thrust the g-pawn another square forward. For the record, Rybka 4 prefers 9.d4.
9.g4 h5 10.h3 hxg4 11.hxg4 Rxh1 12.Qxh1 Qg3+ 13.Kd1 Nxg4 14.Qxd5+ Bd7 15.Nf3
White's play offers a series of instructive inaccuracies. After this final error, checkmate is forced.
15...Nf2+ 16.Ke1 Nd3+ 17.Kd1 Qe1+ 18.Nxe1 Nf2# 0–1
08 November 2011
Lesson of the Week
Checkmate skills
For the beginning players, this week's lesson is an effort to reduce the unnecessary draws in scholastic tournaments. At Saturday's tournament, it seems that every round had at least one player chasing the opponent's king around the board with a queen: check, check, check, ... but never checkmate. Checks can be useful in the drive towards checkmate, but children have an easier time learning the correct technique if they are not allowed to check. For this training exercise, we introduce an artificial rule: no check that is not checkmate.
Players on the attacking end need to learn to control without checks.
Players on the defending side of these efforts, if they are not writing their moves, should ask for a judge to begin counting moves so that a draw by the fifty-move rule becomes a valid draw claim. Normally, a record of the moves is the necessary prerequisite for making a draw claim by the fifty-move rule, or draw by repetition. For beginning students who are playing in tournaments before learning to record the moves, a compromise is helpful. For this reason, we permit a judge to count moves upon request of a player.
Queen vs. King
Start with a king and queen of opposite colors. The player with the queen is not permitted to deliver check. The queen must drive the king to the edge of the board and towards the corner.
When the defending king is reduced to two squares, the other king appears in the far corner. Now, it is checkmate in six moves. The attacking player still delivers no checks until the checkmate. The key to quick reduction of the defending king's space is to move the queen a knight's move from the king.
Keep practicing this elementary skill until the moves feel automatic. It is important to learn to control the king by restriction, rather than assault. Reduce his choices.
Rook and King vs. King
Players who have mastered the elementary checkmate of queen and king against king are ready for one that is more challenging. A rook cannot drive a king to the edge without assistance. But, a rook and king working together can drive the king to the edge without checks.
In our starting position, White can force checkmate in sixteen moves. With our artificial rule in place, it will take more. The rules of chess allot fifty moves. A skilled player should be able to deliver checkmate in less than thirty without having checked the king prior to checkmate.
The rows of red squares mark a barrier that the king cannot cross. At the start, the Black king is trapped in a grid of thirty-six squares. White makes this grid smaller and smaller until checkmate becomes possible. The King might be checkmated anywhere along one of the edges.
To illustrate correct technique, I played against Rybka 4, an extremely strong chess engine. First, I moved my rook far from the other king along the b-file. Then, I brought my king forward. My king kept marching until my rook was in danger.
Stripes,James - Rybka 4 x64
Blitz 5m Spokane, 08.11.2011
1.Rb7 Kd3 2.Kb2 Kd4 3.Kc2 Kd5 4.Kd3 Kc6
5.Rb4
The rook moves to safety. Black's grid, or corral, has been reduced to twenty-four squares.
5...Kd6
If Black tries 5...Kc5, attacking the rook again, then 6.Rd4 reduces the grid to twelve squares.
6.Kd4 Ke6 7.Rb5
7...Kf6 8.Re5
Black's corral had become smaller: nine squares.
8...Kf7 9.Kd5 Kf6 10.Kd6 Kf7
11.Re6
11...Kf8 12.Re7
Black has three squares.
12...Kg8 13.Ke6 Kf8
14.Kf6!
14.Rf7? is a typical beginner's error. From a corral of three squares, the defending king has been given a choice of two corrals: two squares or five squares. Nearly every check offers similar choices. To win efficiently, White must reduce Black's choices.
14...Kg8 15.Kg6 Kf8
We have reached a position that a clever student might recognize as bearing similarity to Problem 9 in Bruce Pandolfini, Pandolfini's Endgame Course (1988). White must keep the Black king from e7 and e8 (red squares), forcing the king to g8 (green highlight). Moving the rook to any yellow square accomplishes this objective.
16.Re5 Kg8 17.Re8# 1–0
For the beginning players, this week's lesson is an effort to reduce the unnecessary draws in scholastic tournaments. At Saturday's tournament, it seems that every round had at least one player chasing the opponent's king around the board with a queen: check, check, check, ... but never checkmate. Checks can be useful in the drive towards checkmate, but children have an easier time learning the correct technique if they are not allowed to check. For this training exercise, we introduce an artificial rule: no check that is not checkmate.
Players on the attacking end need to learn to control without checks.
Players on the defending side of these efforts, if they are not writing their moves, should ask for a judge to begin counting moves so that a draw by the fifty-move rule becomes a valid draw claim. Normally, a record of the moves is the necessary prerequisite for making a draw claim by the fifty-move rule, or draw by repetition. For beginning students who are playing in tournaments before learning to record the moves, a compromise is helpful. For this reason, we permit a judge to count moves upon request of a player.
Queen vs. King
Start with a king and queen of opposite colors. The player with the queen is not permitted to deliver check. The queen must drive the king to the edge of the board and towards the corner.
White to move
When the defending king is reduced to two squares, the other king appears in the far corner. Now, it is checkmate in six moves. The attacking player still delivers no checks until the checkmate. The key to quick reduction of the defending king's space is to move the queen a knight's move from the king.
White to move
Keep practicing this elementary skill until the moves feel automatic. It is important to learn to control the king by restriction, rather than assault. Reduce his choices.
Rook and King vs. King
Players who have mastered the elementary checkmate of queen and king against king are ready for one that is more challenging. A rook cannot drive a king to the edge without assistance. But, a rook and king working together can drive the king to the edge without checks.
White to move
In our starting position, White can force checkmate in sixteen moves. With our artificial rule in place, it will take more. The rules of chess allot fifty moves. A skilled player should be able to deliver checkmate in less than thirty without having checked the king prior to checkmate.
The rows of red squares mark a barrier that the king cannot cross. At the start, the Black king is trapped in a grid of thirty-six squares. White makes this grid smaller and smaller until checkmate becomes possible. The King might be checkmated anywhere along one of the edges.
To illustrate correct technique, I played against Rybka 4, an extremely strong chess engine. First, I moved my rook far from the other king along the b-file. Then, I brought my king forward. My king kept marching until my rook was in danger.
Stripes,James - Rybka 4 x64
Blitz 5m Spokane, 08.11.2011
1.Rb7 Kd3 2.Kb2 Kd4 3.Kc2 Kd5 4.Kd3 Kc6
White to move
 |
| Black threatens White's rook |
5.Rb4
The rook moves to safety. Black's grid, or corral, has been reduced to twenty-four squares.
Black to move
5...Kd6
If Black tries 5...Kc5, attacking the rook again, then 6.Rd4 reduces the grid to twelve squares.
6.Kd4 Ke6 7.Rb5
Black to move
 |
| White was concerned about the square f5 |
7...Kf6 8.Re5
Black's corral had become smaller: nine squares.
Black to move
8...Kf7 9.Kd5 Kf6 10.Kd6 Kf7
White to move
 |
| Time to move the rook |
Black to move
 |
| Black has six squares |
11...Kf8 12.Re7
Black has three squares.
12...Kg8 13.Ke6 Kf8
White to move
 |
| Which piece should move? |
14.Kf6!
14.Rf7? is a typical beginner's error. From a corral of three squares, the defending king has been given a choice of two corrals: two squares or five squares. Nearly every check offers similar choices. To win efficiently, White must reduce Black's choices.
14...Kg8 15.Kg6 Kf8
White to move
 |
| Any yellow square |
16.Re5 Kg8 17.Re8# 1–0
07 November 2011
Tactics Training: Shredder iPad App
Back in January, my initial review of iPad chess applications highlighted Shredder as an exceptional playing program. I noted then that it also comes with one thousand tactics exercises. Although these exercises are not technically difficult, they must be solved quickly to get full credit. Many of the problems are on par with the vast majority found in Fred Reinfeld, 1001 Winning Chess Sacrifices and Combinations (1955). Some are much simpler, requiring the solver to notice a piece that is en prise.
Mike Klein, "Comparing Apps to Apps," Chess Life (October 2011) also recommends Shredder, although his comments might carry more weight if he had tested tChess Pro, which has far better database features than found in the two apps that he recommended for that purpose.
In Shredder, each training problem must be solved before moving on to the next. As time is expended, the number of possible points earned diminishes. Wrong answers diminish the score more rapidly. After too much time, or a couple of wrong answers, the score will be zero. Even then, the problem remains before the solver until a solution is found. In the upper left-hand corner is a question mark. Touching this image causes the piece to be moved to flash. Trial and error, if it comes to that, will eventually reveal the correct move.
Some problems require six moves or more. Many are one or two moves deep. Shredder tracks progress: total score and percentage of possible points. These data is provided for both the whole set, and for the past ten problems. This data can be reset to the beginning.
The Shredder app is not my only resource for tactics training, and so I do not use it every day. I have completed just over seven hundred of the thousand.
Capturing the screenshot and solving the problem above took me less than half a minute. That was long enough to lose one point. After playing Bxc5, a message appears: "You have solved this puzzle and get 9 points!" The message offers two options: stop, which ends the session, and next puzzle, which brings up the next exercise. If it is Black to move, the board will flip. The opponent's previous move is always shown, which eliminates ambiguity concerning whether an en passant capture would be possible. I vaguely recall that such a capture was the correct first move in at least one of the problems.
I plan to complete all one thousand problems, and then begin anew, going through the set a second time with more discipline and consistency. My principal objective the second time through will be to improve my scoring percentage.
 |
| Problem Number 703 |
In Shredder, each training problem must be solved before moving on to the next. As time is expended, the number of possible points earned diminishes. Wrong answers diminish the score more rapidly. After too much time, or a couple of wrong answers, the score will be zero. Even then, the problem remains before the solver until a solution is found. In the upper left-hand corner is a question mark. Touching this image causes the piece to be moved to flash. Trial and error, if it comes to that, will eventually reveal the correct move.
 |
| Playing and Puzzle Ratings |
The Shredder app is not my only resource for tactics training, and so I do not use it every day. I have completed just over seven hundred of the thousand.
I plan to complete all one thousand problems, and then begin anew, going through the set a second time with more discipline and consistency. My principal objective the second time through will be to improve my scoring percentage.
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