23 October 2014

Lesson of the Week

Essentials of Rook Endings

My primary chess club had been divided into groups meeting on different days by age in years past. This year the division was changed to one based on skill. Consequently, my beginning* group on Tuesdays receives different instruction than the advanced group on Thursdays. Members of my in-school chess class and those who have contracted with me for individual lessons will get one or another of these lessons when appropriate.

The beginning group this week is working on recognizing checkmate. Interested parents may contact me to recieve a copy of the Checkmate in One exercise they will be working through over the next several weeks. I created a set of 48 positions from actual play. In every position, there is a possible checkmate on the move. My beginning group worked through the first six this week.

The advanced group is working through developing plans and correctly evaluating a series of positions that arose, or could have arisen, in one of my online games. My game ended in a textbook draw that my opponent insisted upon playing out. Along the way, we both missed clear winning chances during the course of a rook ending.

The first position occured near the end of the game. White recognizes that the position has reached the textbook Philidor Position that he had been aiming at for the past few moves.

White to move

While draws by occupying the third rank with his rook. The game continued 67.Ra3+ Kd4 68.Ke1 e3. Now that Black has advanced the pawn, White resorts to checks from the rear. Black cannot escape these checks and also maintain the pawn.

69.Ra8 Ke4 70.Re8+ and the game went on another twelve moves with White continuously checking the Black king.

The second instructive position comes from the moment when Black missed a win.

Black to move

After 54.Ra4+, Black played 54...Kd5. 54...Kd3! on the other hand would have facilitated the advance of the e-pawn and victory.

In the third instructive position for this week, White missed a chance for a clear advantage.

White to move

Black has just played 42...f5? White played 43.c4 and later let the game slip further away. However, he might have played 43.h4!

After 43.h4, Black's best chance requires the sacrifice of a pawn. 43...f4 44.Rxf4 Rb5+ 45.Kc4 and White has a clear advantage, albeit not necessarily a winning advantage.

There are many interesting positions that arise after 43.h4! Kd7?

One that is part of my lesson plan arises after the continuation 44.Rf4 Kc6 45.a4 Kd6 46.c4 Kc6 47.a5! b5

White to move

White's best move appears to be 48.d5! A possible line is 48...exd5 49.cxb5+ axb5 50.a6!

Either the a-pawn will promote, or all of both sides' pawns on the a- through e-files will be liquidated and the White king will march over to nab the trapped rook.



*Beginning and advanced are fuzzy terms in the chess world. From the perspective of a super-Grandmaster, everyone under 2000 Elo is a beginner. That definition includes me. For purposes of my after school chess club for elementary age children, advanced players are those who have qualified for the Washington State Elementary Chess Championship. Qualification each year requires scoring 3/5 or better in a qualifying tournament.

19 October 2014

Opportunity

When a tactical opportunity presents itself, seize it. Perhaps Black thought that he won a pawn with 33...Nxf2. This position arose in Miroshnichenko -- Rychagov, Sochi 2005. I found the game while exploring options for Black in the Catalan after 6.Qc2 dxc4 7.Nbd2, which scores very well for White.

White to move

18 October 2014

Knight Forks

When I get a new copy of Chess Informant, I play through all of the games published therein that are classified C00-C19. These are the Encyclopedia of Chess Openings (ECO) classifications for the French Defense.* New on my computer are the download versions of CI 119, CI 120, and CI 121. These electronic publications are in ChessBase format.

This morning I glanced through an excellent instructive article on pawn endings in Informant 120, "Precision" by Eduardas Rozentalis. Then I started working through the French Defense games. Naturally, the tactics in these games are instructive.

The position below appears in the notes to CI 120/100 Solak -- Bartel, Yerevan 2014.

White to move

The correct move in this position is the final one in Solak's annotations. He leaves the reader to work out why it is a winning move.

I may use this position with some of my students next week. After White's move and an obvious looking subpar response by Black, a position is reached that may be useful with some of my beginning students.


*ECO Code is a trademark of Chess Informant.

16 October 2014

Superficial Analysis

Correcting Errors

There is no substitute for calculation. Intuition can be helpful in chess and sometimes even helps humans see some things that computers miss. However, a quick glance and reliance upon intution can mislead.

In yesterday's post, "The Final Transition," I offered the view that an exchange of bishops that had not taken place was necessary to avoid because it would have given White a clear win. I was wrong. That position is still a draw.

Black to move

In the game, Black played 47...Bb4+.

I stated in "The Final Transition" that 47...Bxd4+ was a losing move for Black. I saw at a glance 48.Kxd4 axb3 49.axb3 and judged this position as "hopelessly lost" for Black.

Black to move

White does indeed win after 49...Kb4 50.Kxd5 Kxb3 51.Ke5 Kc4 52.Kf6 Kd5 53.Kg7 Ke6 54.Kxh7

Black to move

However, Black has another option: 49...Kc6!

After 50.b4 Kd6 51.b5 Black has 51...g5!

White to move

When White wins the h-pawn, Black will be able to trap the White king on the h-file. In the diagram presented above for the line that began 49...Kb4, White had a reserve tempo with the pawn. In this last position, that is no longer possible.

I had stated in "The Final Transition" that intermediete students would find the position in the first diagram above instructive. Although I have corrected my own understanding of the consequences of the bishop exchange, I still believe the position will be useful. It will the lesson with my chess students today.

15 October 2014

The Final Transition

While beginning to explore the exciting material in Chess Informant 121, I came across an ending of value to intermediate students. In this game from the recent Olympiad, Markos -- Leitao, Tromso 2014 (CI 121/82), White sacrificed his queen for the purpose of placing a dangerous pawn on the seventh rank.

Black to move

Black played 34...Qd8 and twenty moves later the game ended as a draw. Chess teachers can find several positions in the last twenty moves worth putting in front of beginning and intermediate students with a question: should Black exchange bishops?

For example, After 47.Bd4.

Black to move

The average reader of Chess Informant does not need a prompt to recognize that 47...Bxd4 offers Black a hopelessly lost pawn ending.* However, this position should prove instructive when I put it in front of youth players who are struggling to rise to the level of solid C and D Class players.

Back to the first diagram, Rafael Leitao, who annotated the game for Informant noted the pitfall that he avoided. 34...Kf7? 35.Bxe7 Kxe7 36.Rc8 Qa5 37.d8Q+ Qxd8 38.Rxd8 Kxd8 39.Kf1.

Black to move


White would have had an elementary win in this pawn ending. Even so, my students may need to play this position out a few moves in order to understand how White wins.

After White's queen sacrifice, Black had to examine the bishop and pawn ending as well as a couple of possible pawn endings. Kf7 would be played, but the move order was critical. Black chose the correct transition to an ending with the bishops on the board.


* Edit 16 October: My superficial analysis led to gross error. The position that would have resulted had Black opted to exchange bishops on move 47 is not "hopelessly lost" for Black. See "Superficial Analysis".

10 October 2014

Compensation

Does White have compensation for the sacrificed pawn? How should Black proceed?

Black to move

30 September 2014

Top 100!

It never crossed my mind that I would be on any list of the Top 100 chess players, although it might have. When I reached my peak USCF rating slightly more than two years ago, I was in the top 60 active players in my state.

But a Top 100 national list is another matter. Hence it came as a surprise in July when I received an email from the USCF seeking to verify my age because I may be eligible for a Top 100 list. I provided the verification and then checked the list. My rating was several points below number 100.

A week or two later, I played in a local event at the my chess club and tied for first with an 8-1 score. I beat the other top player in our individual encounter, but lost to one of those who finished at 6-3. My USCF Blitz rating shot up from 1894 to 1939. That would have put me at number 92 on the August list. However, my new rating become official on September 1.


Top 100 list are updated at mid-month, but staff vacation delayed the September lists. I had to wait a long time, but I am now officially on the list of the Top 100 USCF Blitz Players over the age of 50! I am number 96. I likely will drop from the list next month.

There is no one else from my state on the list. That absence is a function of the newness of the USCF blitz rating and the paucity of events. The list cannot be taken too seriously. I am certain there are some players in Seattle my age or older who can school me at blitz. Even so, it's nice to be on a list.

28 September 2014

Playing all Night

Sometimes I play online blitz or bullet all night long. Sometimes this reckless behavior stems from trying to swing my way through a slump.* After I lose several games that I should have won, I keep playing until my performance improves. Other times I play all night because I am angry and cannot sleep, or I cannot sleep because there is trouble in the neighborhood. Maybe sleeplessness stems from my dogs being agitated and noisy, or due to travel or stress.

Last night I had a three hour blitz session relating to care some family responsibilities.

These all night sessions generally produce more losses than wins. My errors are often elementary. These games fill my database with intructive errors that can be used teaching beginners.

On my previous move prior to this position, I could have snatched the pawn.

Black to move

Instead of moving my king, forcing my opponent's king to b5, I played Qb8 and stalemated my adversary.

This position is less elementary.

Black to move

One move gives me an advantage, all others lose. My opponent drew the game with repetitive checks after my Kf7.

In this position from an Exchange French, Nxe5 is simple and correct.

Black to move

I played Nxd4 and quickly found my position hopelessly lost.

Here I had an advantage against a player rated more than 400 Elo above me.

White to move

I considered 42.Kxg5, but played the inferior 42.Kh3. After 42...Re3 43.Kg4  Rxb3 44.Rxa5 Rb2, I stillcoul have taken the g-pawn and been better.

White to move

Instead, things remained balanced with 45.Kf5 Rxh2 46.Ra7+ Ke8 47.d6 Re2 48.Kf6 h3 49.Rh7 h2

White to move

Here 50.a5 is the only move that maintains equality. Alas, the last few moves have been sheer panic after blowing a nice position. I played 50.Kxg5 and resigned a few moves later.

Happily, I won six of the next seven games. The one blemish in that series in the stalemate above.


*A baseball metaphor. See "You just swing through it."