30 September 2015

Child's Play

A two pawn advantage in a rook ending should be decisive. Indeed, I won easily with such an advantage last night in a three minute blitz game. The win seemed child's play.

A few minutes of postgame analysis this morning revealed another story. I made a fatal blunder and won because my opponent missed a critical opportunity.

Black to move
After 46.Ke2
46...g5 47.Kf3 gxf4

47...Kg6 is better. 48.Rxg2 Rxg2 49.Kxg2 g4 and the pawn ending is an elementary win for Black.

48.exf4 e5 49.fxe5+ Kxe5 50.Re1

Black to move

50...Kf6??

It was necessary to move the king to the d-file. 50...Kd4 was best.

51.Rg1??

51.Kf2 Rg5 (51...f4 52.Rg1=) 52.Rb1 Rg8 and the computer thinks that Black has a slight edge. Accurate play by White should hold the draw.

White to move
Analysis Diagram after 52...Rg8

The Drawing Method

From the analysis diagram, I played out the position against Stockfish. Perhaps the drawing method is not as simple as the win became in the game, but it requires only application of some elementary techniques.

Stripes,James -- Stockfish 6 64

53.Ra1 Ke5 54.Ra5+

Side checks are the key drawing method until White's king gets too close to the rook, then either restraining the advance of the f-pawn or rear-checks become necessary. Although not a textbook Philidor position, the drawing method follows the same idea.

54...Kd6 55.Ra1 Rg7 56.Ra6+ Kc5 57.Ra5+ Kb4 58.Ra1 Kc3

White to move

59.Kg1

59.Ra3+ fails to Kb2.
59.Rg1 fails to Kd2.
59.Rd1 fails to f4.

59...f4 60.Ra4 Rg4 

60...f3 is met by 61.Rf4

61.Ra3+ Kd4 62.Ra4+ Kc5 63.Ra5+ Kb4

White to move

64.Rf5

White now prevents f3.

64...Ka3 65.Rf8 Kb3 66.Rf7 Kc2 67.Rf8 Kd3 

White to move

68.Rd8+

With the White king able to support f3, he must be harassed endlessly with checks from the rear.

68...Ke2 69.Re8+ Kd1 70.Rd8+ Ke1 71.Re8+ Kd2 72.Rd8+ Ke3 73.Re8+ Kf3

White to move

74.Ra8

Preparing to resume checks from the side.

74...Ke4 75.Ra4+ Kf5 76.Ra5+ Ke6 77.Ra6+ Kd5 78.Ra5+ Kc6 79.Rf5

Again restraining the f-pawn.

79...Kd6 80.Rf8 Ke6 81.Re8+ Kf6 82.Rf8+ Kg7 

White to move

83.Rf5 Kg6 84.Rf8 f3 

The computer gives up.

85.Rxf3 Kh6 86.Rf2 Rg5 87.Rxg2 Rc5 88.Rf2 Ra5 ½–½


The Actual Game

After 51.Rg1?? in the game, we reached this position.

Black to move

51...Kg5

This was Black's only winning move, but is was simple to find and I played it automatically.

52.Kf2 f4 53.Kf3 Rg3+ 54.Kf2 Kg4 55.Re1

Black to move

Now, it is time to convert the rook ending into an elementary pawn ending.

55...g1Q+ 56.Rxg1 Rxg1 57.Kxg1 Kg3 58.Kf1 Kf3 59.Ke1 Kg2 and White resigned.

29 September 2015

Strategic Nuances

This position, which I came to via Karpov -- Timman, European Junior Championship, Groningen 1967-1968, has appeared on the board at least 119 times.

Black to move

Jan Timman played 5...Ba5.

Anatoly Karpov wrote:
The bishop is badly placed at a5, and the whole of White's subsequent play is built on exploiting this circumstance. I consider that Black should have taken the knight, and then played Nc6...d6...and e5.
Anatoly Karpov: Chess is My Life (1980), 28.
Karpov won this game and the championship. He had the Black side of this position against Victor Korchnoi in 1993 and played 5...Bxc3.

Timman's move has been more popular, having been played at least 86 times to 32 for 5...Bxc3. However, White's score against 5...Ba5 has been 67%, while White has scored 56% after 5...Bxc3.

Why is a5 such a poor spot for the bishop?

Karpov elucidates two resulting vulnerabilities in the ensuing comments. One, the presence of the bishop on a5 prevents Black from playing b6, and hence the c5 pawn is difficult to defend. Two, he offers some unplayed lines in which White either wins a piece through tactics, or White's central pawns become mobile at the cost of a pawn.

In the game itself, White's pieces became more active. Under the pressure of an inferior position, Timman blundered away a pawn.

28 September 2015

A Better Day

Taking Care of Business

After losing my round two game and taking my usual round three bye, I started Sunday morning with 1.5/3 in the Eastern Washington Open. My round four opponent is returning to chess after fifty years away and is much stronger than his rating suggests. Even so, he missed a tactical finesse that gave me an opportunity.

Black to move

In round five, I had my third Black in four games. I spent some time with the tournament director looking at the pairings, the logic, and the alternate possibilities. Due to a large number of byes and several upsets by the oldest and youngest players in the event, someone had to forego the usual color equalization. My opponent should not have three Blacks in a row, so he had White.

While I played something resembling the Czech Benoni in round four, I opted for a more normal Modern Benoni in round five. When my opponent played the thematic e4-e5 push, I spent nine minutes working out the best response. Prior to that I had averaged one minute per move.

Black to move

Would you play these two positions the way I did?

I finished the event with 3.5/5 and tied with a bunch of players in third place, sharing the A Class prize with two others. The only Expert went 5-0. All of the A Class players suffered a loss, some more than one. One of my students took out two A Class players on Saturday. The young woman who beat me on Saturday beat another A Class player in round five.

27 September 2015

A Nice Win

Simple Chess

I have been playing correspondence chess on ChessWorld.net for eleven years, longer than any other site where I play at present. It was the third website that I joined for this sort of chess. First was Net-Chess.com in early 2003. Then GameKnot. Ironically, someone in the forums at GameKnot alerted me to the existence of ChessWorld.net. Someone alleged that ChessWorld.net was created by a disaffected former GameKnot member and that CW was inferior to GK. I decided to take a look for myself.

ChessWorld.net is vastly superior to GameKnot in my opinion. The site design is more robust and users have far more options for tweaking the interface. A nice feature of CW that I have not found on other sites is pie charts showing a player's performance.

My Performance
Although I have an overall positive record, my score is 50% in my usual rating group (2000-2200). I have recently risen above 2200, and had done so in the past as well. Staying there may prove difficult. My peak rating on the site is 2262 (280 above my peak USCF). Against opponents above 2280, I have only seven wins in 56 games. Four of these have been on time. Three times I have outplayed my opponent in the top several rating groups.

Pie charts for various rating groups shows how I have performed against those rated higher than me.

Performance Against 1800+

My third earned victory over a player above 2280 ended last night. The game began at the end of July 2014. My opponent played the Budapest Gambit, an opening that has given me trouble over the years.

I only checked two positions in my annotations with Stockfish.

Stripes,J (2202) -- Internet Opponent (2355) [A51]
www.ChessWorld.net, 31.07.2014

1.d4 Nf6 2.c4 e5 3.dxe5 Ne4 

3...Ng4 has given me trouble in a few games.

4.Nf3 d6 5.Nbd2 Bf5 6.Nxe4 Bxe4

White to move

7.Qb3N

7.Ng5 has been played in a couple of games, and is the engine's choice. I had the notion to play this move next. 7...Bg6 8.e6 fxe6 9.Nxe6 Qd7 10.Nf4 led to a win by White in 42 moves in Veingold,A (2465) -- Carpintero,J (2265), Linares 1994.

7...Bxf3 8.exf3

8.Qxf3 Nc6 9.exd6 Bxd6 struck me as offering Black good compensation for the pawn. Instead, I wanted to get my pieces into play. I was spending a lot of time on Paul Morphy's games during this phase of the game. That probably influenced my decision.

8...b6 9.exd6 Bxd6 10.Be2 0–0 11.0–0 Re8 12.Be3 c5 13.Rad1 Qc7 14.g3 Nc6 15.Rd5 Rad8 16.Rfd1

Both players have completed their development, as the classicists say.

Black to move

16...Ne7 17.R5d2 Nf5 18.Bf1

Removing the bishop as a potential target so my rooks would be free to roam on the d-file.

18.f4 was an alternative.

18...Nxe3 19.fxe3 Be7 20.Rd5 Bf6 21.Kg2 Qe7 22.Qd3

Black to move 

Offering the b-pawn. I was willing to trade rooks if I also could swap queens and keep an extra pawn.

22...Rxd5

22...Bxb2?? 23.Rxd8 Qxe3 (23...Rxd8 24.Qxd8+ Qxd8 25.Rxd8#) 24.Qxe3+-.

23.cxd5

I like having a passed pawn backed by heavy pieces.

23...Bxb2?

I am not certain that this move was Black's most significant error, but my road to victory seemed relatively uncomplicated afterwards. I had to attend to simple tactics and a lot of queen maneuvers.

23...Rd8 24.d6 Qe6 25.b3 Be5 26.d7 and White's advantage seems less significant.

24.d6 Qd7

24...Qf6 25.d7 Rd8 26.Qe4 Kf8 27.Bb5 Qe7 28.Qxh7 g6 29.Qh6+ Bg7 30.Qf4±.

25.Qb3

Black to move

A fork of piece and square.

25...Re6

25...Bf6 26.Bb5+-.

26.Qxb2+- Rxd6 27.Rxd6 Qxd6

I would like to trade queens, but my opponent understands this goal and refuses to cooperate. As long as his queen remains, he has the chance, however remote, to force a draw by repetition or even to sneak in a checkmate.

28.Qc2 Qe7 29.Qd2 g6 30.Kf2 Kg7 31.e4 h5 32.h4 Qe6 33.Qd5 Qe7 34.f4 f6 35.Bc4 Qe8 36.Ke3 a6

White to move

37.Qb7+! 

Another fork. This move eliminates Black's chances for counterplay with his queenside pawns.

37...Kh6 38.Qxb6 f5

Decision time.

White to move

39.Qxc5

I was willing to suffer some checks, secure in the knowledge that my queen and bishop were well positioned to weave a mating net once Black had driven my king to h3. Of course, I had to verify that my opponent would not have a free move to play Qh1#!

39...Qxe4+ 40.Kf2 Qc2+ 41.Kg1 Qc1+

I expected 41...Qb1+ 42.Kh2 Qb2+ 43.Kh3 Qb8.

42.Kg2 Qc2+

Still expecting 42...Qb2+ 43.Kh3 Qb8.

43.Kh3 Qc3

43...Qe4 44.Qf8+ Kh7 45.Bg8+ Kh8 46.Bf7+ Kh7 47.Qg8+ Kh6 48.Qh8#.

44.Qf8+

Black to move

44...Kh7

44...Qg7 45.Qxg7+ Kxg7 46.Bxa6+-.

45.Bg8+ Black resigned 1–0

I had played relatively slowly through the first 25-30 moves and had lost the other game with this opponent on time because I failed to log in one weekend. The game was seven days per move. My opponent had slowed down and played each move this summer when he was under twenty hours remaining.

After playing 45.Bg8+, I left him a note with the moves to checkmate. With one day remaining on the clock, he resigned.

26 September 2015

Bad Day

My first day's performance in the Eastern Washington Open was sub-par. In the first round, I missed a key defensive resource and found myself on the Black side of this position.

White to move

Fortunately, my opponent missed the key move here and I was able to defend. We swapped off pieces and I anticipated an ending with a bishop and four pawns against seven pawns. Instead, my opponent dropped a rook in an even position and then resigned.

In the second round, I had White against a young woman who I had briefly coached a few years ago when she was preparing for the Idaho Girl's Championship.

White to move

I made the wrong move here and quickly lost.

How would you play these two positions?

25 September 2015

Corralled

Yesterday, I started reading an old book that had been sitting on the shelf: Anatoly Karpov and Aleksandr Roshal, Anatoly Karpov: Chess is My Life, trans. Kenneth P. Neat (1980). The book contains two of Karpov's games from the Masters vs. Candidates, Leningrad 1966. In the first of these, Alexander Chistiakov managed to get his knight trapped on a7.

White to move

Chistiakov played 28.e4, losing the knight to a simple fork. I wondered why he did not play 28.Nb5. It did not take long to find the refutation.

18 September 2015

Knight Award Problems

The twelve problems for the Knight Award require some tactical understanding on the part of the student. One problem has two solutions that are checkmate in five. Another problem has two correct solutions--one safe, one risky. When testing students, I accept either answer, but then make the student play out the position.

These problems are part of a series of 150 that I call Checkmates and Tactics. There are six checkmates in one for the Pawn Award. These twelve. For the Bishop Award, there are twenty-four problems, half leading to checkmate. The number increases to forty-eight for the Rook Award. Sixty Queen Award problems cap the series.

My awards become progressively more difficult. Only strong and devoted students will progress through the Rook and Queen Awards.

Knight Award: checkmates and tactics.

Find the move or combination that wins material or leads to checkmate in each position. White moves first in each. Eight end in checkmate; four result in gain of material.*














*Ten problems are from actual games. Two are composed problems published in 1512 by Pedro Damiano.

16 September 2015

Pawns are the Soul

Pawns are the soul of chess.
François-André Danican Philidor
In my post, "Dominquez--Aronian, Tata Steel 2014", I mentioned that Levon Aronian's play in that game offered a modern lesson in the meaning of Philidor's famous dictum. This morning I looked at Aronian -- Ponomariov, Tsaghkadzar 2015, Chess Informant 124/9, and found another illustration. The game as a whole is a good illustration of piece play in the service of creating powerful passed pawns.

Here is one of the final critical positions.

White to move

What would you play?

Aronian sacrificed the exchange to get the a-pawn rolling. Ponomariov resigned ninen moves later.

15 September 2015

Dear Chess Parents

I am certain that your child will enjoy chess club. Perhaps you think of chess as a game that your child enjoys, or perhaps you think of it as something more than a game.

Benefits of Chess

Chess may improve your child's academic skills, emotional skills, and social skills. Chess improves mental skills of observation, pattern recognition, memory, analysis, logic, and critical thinking. Studies have demonstrated clear improvement in math and reading skills for students receiving a few hours of chess instruction per week. Chess competition encourages growth in the personal qualities of patience, self-control, coping with frustration, self-confidence, and self-esteem. Playing chess develops sportsmanship, responsibility, and respect for others. See "Benefits of Chess" for a slightly expanded list.

None of these gains are automatic. When skills learned in chess club are practiced at home, the benefits of chess develop. Chess skill also improves.

What Happens in Chess Club?

My youth chess clubs include in-school and after school groups across several age levels. There are also classes that function much like clubs. At least half of the time of chess club is spent playing chess, but there is also time for instruction.

Instruction may be as short as a few minutes or as long as half an hour. It varies week to week. Each week, I prepare a set of lessons. Lessons vary in difficulty and usually include elements designed to aid the skill development of everyone from beginners to seasoned tournament veterans. Often there are worksheets with elementary tactics exercises, and there is always a strategy or tactics problem. Sometimes there are a series of such problems arising from a single previously played game. The history of chess from the earliest recorded games more than five centuries ago to games played in tournaments today offer an inexhaustible source for chess instruction. Hence, my "lesson of the week" is rarely repeated.

I make an effort during chess club to work with each child individually, teaching and testing skills. My chess awards provide structure to these lessons. The awards are sequenced according to the relative value of the chess pieces: pawn, knight, bishop, rook, queen, and king. Each award is progressively more difficult than the preceding one. A child who works through the Rook level will become one of the top players in the area.

When a child can explain the basic rules and recognize checkmate, he or she earns the Pawn Award. The rules concerning castling and en passant are difficult for most young players. The next award is the Knight. To earn this award it is necessary to master elementary checkmates with rooks and queens, as well as other skills. Beginning with the Knight Award, the tactics problem worksheets that are part of each award can seem daunting. The twelve problems on the Knight Award worksheet involve some sophisticated tactical skills and knowledge of checkmate patterns.

These Knight Award problems are posted.

More information on the Knight Award can be found at "Lesson of the Week" (18 October 2011).

12 September 2015

From the Benoni

I had this position a couple of months ago in a correspondence game. The computer says that I squandered an advantage. How should White play?

White to move

10 September 2015

Glossary of Tactics: Skewer

When two pieces are on the same rank, file, or diagonal, they may be attacked by a pin or skewer. A skewer is a pin in reverse. The stronger or more vital piece stands in front of another target. When it moves to safety, the piece behind it is captured.

White to move

This position arose in Gioachino Greco's model games after 1.e4 e5 2.Nf3 Qf6?! 3.Bc4 Qg6 4.O-O Qxe4 5.Bxf7+ Ke7.

After the alternative, 5...Kxf7, White wins the queen with a fork.

The key move is 6.Re1, attacking the queen and pawn along the e-file. After 6...Qf4 7.Rxe5+ captures the pawn with check.

One of Greco's studies concluded quickly with 7...Kd8 8.Re8#.

Hence, 7...Kxf7 is obligatory. Greco shows that even here, the king's vulnerability is fatal.

8.d4

White supports the rook and attacks the queen via discovery.

8...Qf6 9.Ng5+ Kg6 10.Qd3+ Kh5 11.g4+ and checkmate next move.

The term skewer also applies when the two targets along a line, such as when two rooks are vulnerable to attack by a bishop.

White to move

White played Bc6, winning the exchange.

The term skewer appears to have entered the vocabulary of chess players in the late 1930s in Liverpool, England. There, Edgar Pennell, who was not a particularly strong chess player proved that his teaching methods were effective in training a group of school boys to be much stronger than he was. Edward Winter has an informative history of Pennell work and chess terminology in his Chess Notes article, "The Chess Skewer" (updated 26 October 2014).