03 June 2011

Back to the real (problem chess) world

Looking back at last month's posts, one might get the impression chess problems mainly deal with all kinds of boards, strange chess pieces, special rules and lots of other weird stuff. Examining all that through the glasses of a chess player, this might not be overly attractive. In fact, fairy chess is not even fascinating all problemists! So, let's return to compositions which are most probably more appealing to the majority of chess enthusiasts — endgame studies.

Though a lot of endgame studies look as if they occured in an actual chess game, they're still made up, products of composers' creative activity. As to the number of moves, there is no restriction. Nevertheless, the aim - draw or win with the white pieces - has to be achieved in a unique way against any defense.

Most probably, a study with, say, at most ten pieces is what a casual solver would accept as a composed endgame. But, as already mentioned, a study is not an endgame in terms of the final stage of a game. Therefore, there can be way more pieces on the board. Actually, I have seen some studies with a piece count of 15 and more. But I can't say I like many of them.

An interesting question is how to solve a study. You only have the stipulation, nothing else. Unlike in a mate problem with its constraint to deliver checkmate after the given number of moves, you don't have exact hints when you have found the complete solution of a study. For example, at which point can you say it's a draw as demanded? Not all variants of a study end with a stalemate or the position king vs. king, so that you can determine the result easily.

Recently, I saw a nice recipe how to proceed when making solving attempts:
  1. Examine the material.
  2. Examine the stipulation.
  3. Examine the position.
  4. What are Black's threats?
  5. Can you list the White defenses to the threats? Play one of them.
  6. What are White's threats?
  7. Choose a reply for Black.
  8. Repeat steps four to seven as long as necessary.

We might try that now. Obviously, I have found something appropriate for demonstration purposes. ;-)

A. A. Troitzky
Novoye Vremya, 1895
[8/8/8/8/3k2K1/5R2/5Ppb/8]
White to move and draw (3+3)
  1. Examine the material.
    White has a rook against a bishop. This is a normal draw.
  2. Examine the stipulation.
    White is to draw, but as it is a normal draw anyway there must be a catch somewhere.
  3. Examine the position.
    The catch is clear. Black has a pawn about to queen resulting in an enormous material advantage.
  4. Black's threats?
    As already stated: Black will promote on g1.
  5. White's defenses?
    This is not easy. 1. Kh3 does nothing about the threat, and 1. Rg3 Bxg3 makes things even worse. So, knowing that there is a solution, we hunt for clues. One clue is that, for drawing purposes, White has too much material. He needs only to capture the g2 pawn at any price to settle the result. There do not seem to be any other clues. That the stipulation is a draw suggests a stalemate possibility, but only an experienced solver would suspect stalemate here. Even if there seems no point, let's try a rook sacrifice. 1. Rf4+ Bxf4 2. Kf3 g1=Q is a dead end for White, so try 1. Rd3+.
  6. White's threats?
    Of course, White wants to play 2. Rd1 on the next move.
  7. Black's reply?
    The only way to spoil White's intention is 1. - Kxd3.
  8. Black's threats?
    Black still threatens to queen his pawn.
  9. White's reply?
    2. Kh3 still is not good, as it wasn't before, but 2. Kf3 attacks the black pawn, blocks the white pawn, and invites 2. - g1=Q (or R), which ... is the stalemate we hoped to get. Weeeeeeeeee! White's rook sacrifice did three things: 1) got rid of a superfluous piece; 2) enticed the black king onto a desired square (completing the stalemate net forcibly); 3) vacated a square for the white king.
    What about other Black promotions, to knight or bishop? No stalemate then. But after 2. - g1=S+ 3. Kg2, White takes one of the black pieces and it's a draw. 2. - gl=B leaves Black with two bishops on the same colour, and no black pawns — draw.

Argh! Due to lack of time, this post got shorter than intended. Watch out for more, soon!

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