Tuesday, February 19, 2008

Another Example of Applying Basic Endgame Knowledge

Here's an example from a recent game where knowledge of a basic endgame helped resolve a more complicated position.

In the case of King and Rook's Pawn vs. King, the defender draws if their king gets in front of the rook pawn. Barring that, if the king can reach the B7 or B8 squares (e.g. f7/f8 vs. an h-pawn), it prevents the attacking king from reaching the key N7/N8 squares (e.g. g7/g8 vs. an h-pawn).

{Aside: although I normally use algebraic notation, the old descriptive notation has one advantage in cases such as this: it doesn't matter if we're talking about white or black queening the pawn, or whether it's the queen's or king's rook pawn.}

For example, in the following position:

Black draws if their king gets to one of the green squares; White wins if their king gets to one of the yellow squares. For example, with Black to move in the above position, 1...Kd7 2.Kg5 Ke7 3.Kg6 Kf8! and Black's king reaches the f8 square and secures a draw:

There are two basic drawing ideas from this position: either get the defending king in front of the rook pawn, or trap the attacking king in front of its pawn.

For example, 4.h4 Kg8! and the king reaches the corner:

White, at best, can stalemate Black (e.g. 5.g5 Kh8 6.h6 Kg8 7.h7+ Kh8 8.Kh6 =).

If White tries to get his own king ahead of the pawn, it can be trapped on the h-file, e.g. after 4.Kh7 Kf7!

As long as White's king is on h7 or h8, preventing Black from reaching g8 and h8, Black keeps his king on the drawing f7/f8 squares. Eventually White will either advance his pawn as far as possible and be stalemated, or he'll try to get his king off of the h-file (e.g. moving to g6), which allows Black to play ...Kg8 and reach the previously described drawing scenario.

There is one exception to this rule that the defender will draw by getting to the B7/B8 square first:

Here, 1.h7! prevents 1...Kg8 and wins.

Studying basic endgames allows you to spot favorable transitions (or avoid unfavorable transitions) to them from more complicated endgames. An example occurred in one of my recent ICC games, where I had White:

If White chooses to capture the d-pawn, does he have to be afraid about Black trading off all the rooks and threatening to queen the h-pawn? {Fritz actually prefers 39.Rg2+!, but we'll let that slide}. No. After 39.Rxd4 Rxd4+ 40.Rxd4 Rxd4+? (Keeping a rook offers the best defensive chances for Black), 41.Kxd4+- Kxf5:

Black has traded down to a lost pawn endgame. On the kingside, we have the standard draw vs. a rook's pawn. However, White has a majority on the queen's side, which wins on its own. The game concluded: 42.b4 (no rush) Kg4 43.Ke4 (or 43.a4--still no need to rush) Kh3 44.Kf3 Kxh2 45.Kf2:

and now the win is clear. The game concluded 45...Kh3 46.a4 Kg4 47.b5 axb5 48.axb5 h4 49.b6 h3 50.b7 h2 51.Kg2 1-0.

If you've avoided studying endgames up to this point, hear me now and believe me later: mastering these basic positions will help your chess.

Reference: Secrets of Pawn Endings, by Muller and Lamprecht

1 comment:

Chessaholic said...

Your posts are always insightful. Good stuff.