Sunday, September 02, 2007

Two endgames

I have a couple of endgame positions from recent games at the local coffeehouse. There is no doubt the importance of the endgame. It's also true that the endgame is so rich, you'll never run out of interesting things to study there. Exhibit A is likesforests who has had numerous very good blog posts on the endgame.

Position 1, a win with bishops of opposite colors!

White to move

This game could easily have been drawn until Black made two mistakes to lose it. The first, is losing a pawn of f6 so that white's f-pawn is now a passed pawn. The second is becoming too aggressive with the king. If the king were back to stop the f-pawn, the game would still be drawn. Now white wins with Be5 and f5. Black must play Bc3 to stop the pawn allowing white to take on e4 and support the f-pawn with the king, eventually winning black's bishop and g-pawn.

The second position is a king and pawn endgame that features a combination of interesting techniques.

White to move

White has to be able to envision that this position is winning (or at least drawn) before entering into it. Black has a passed pawn on the a-file so white's king is tied down to stopping that threat. In the meantime, how does white stop black from marching into e4 and taking the e3 pawn?

The answer is a kind of breakthrough. If the black king ever comes to e4, white wins by playing b5! where black cannot stop a pawn from queening, e.g. cxb5 c6 or Kd5 b6. So now we realize that e4 is forever off limits to the black king due to this breakthrough. This means that in the diagrammed position white can play Kb2! and go take the a4 pawn without fear of losing since black can make no progress.

The question then is whether or not this will win or draw for white after Kb2! Kd5 Ka3 Kc4 Kxa4 Kd5:

White to move

Now white's plan is to go after the a-pawn. Let's look at the direct route: Ka5 Kc4 and now if Ka6 Kxb4 is not good for white. Note that if the pawn is on a6 instead of a7, Kxa6 Kxb4 Kb6 wins for white. This means that black can never advance the a-pawn to a6. As a result, black will forever be doing a king shuffle on c4, d5, and e6. And, in order to stop white's plan, the king must move to c4 when white plays Ka5. Since he can only get there from d5, the black king can be triangulated. Kb3! Ke6 Ka3! Kd5 Ka4 Kc4 Ka5 Kd5 Ka6 Kc4 Kxa7 Kxb4 Kb6 wins the b-pawn and leads to promotion.

Final caveat. When white has his king on a4, the pawn break doesn't work because after b5, cxb5+ is check. So if black plays Ke4 while the white king is on a4, white plays Ka5. Then Kxe3 is met by the breakthrough and Kd5 is met by Ka6.

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4 Comments:

At 12:49 AM, Blogger likesforests said...

I really enjoyed these positions, especially the king and pawn ending. There were a couple "Aha!" moments as I worked to solve it--first as I realized I could grab the a-pawn with impunity, second when I realized I had to return to the center to win.

 
At 9:54 AM, Blogger Loomis said...

The king and pawn position was remarkable to me because it doesn't appear at a glance to be that special, but it turns out that white absolutely dominates the position.

I also forgot to mention that there are over 20 consecutive ply that are king moves. This is amazing. The king could go around 3 sides of the board in that many moves. So, as it turns out, in complicated K+P endings, the board somehow gets bigger -- in the sense that there are more places to go.

 
At 3:27 PM, Blogger transformation said...

Loomis, fyi, my big post on my annual plan or two year plan is done. cf post if you care to. the whole enchelada. warmly, dk

 
At 4:37 AM, Blogger IA said...

If you want to explore a practical new approach to chess visualization based on 800 positions taken from real games, then check out my blog here.

This new approach to chess visualization training will stretch your vision from 4 to 39 half-moves while expanding it from 1 to 2 to 3 sectors of the board.

Chapter 8 of the Chess Visualization Course is on "Exchanging to a Won Ending" and contains 36 exercises similar to what you are talking about here. Eight of these exercises ask you to visualize endings that range from 21 to 39 half-moves! None of these exercises are given on the blog, unfortunately, but email me at info@chessvisualization.com and I'll try to send you one. Please reference this comment to refresh my memory!

 

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