Endgame Observations

(Red Hot Pawn, Correspondence Game, 12/19/2005) (Black to Move)

Here is a fascinating position I came across in a correspondence game just yesterday. With black to move, all eyes are on the c3 pawn. It is two ranks away from promoting, but, alas, the white king is fast on its tracks. Still, this diversion should be enough. As the white king chases the black pawn down the c-file, the black king can ease on over to the king side and munch up white's pawns.

So here's the key issue? Should black continue to lead the white king astray (1... c2) (red below) or should black put his king in motion towards the king-side pawns (1... Ke6) (blue below)?

Believe it or not, this is a crucial decision for black. One wins the game, the other loses it!

The right move is 1... Ke6!. This is best examined by the situation of the pieces after the white king captures the c-pawn (this is a guaranteed move--without such a move black's pawn would queen and white would easily be lost).

The two diagrams above tell the whole story. In both, white's king has just captured black's c-pawn (albeit at two totally different locations). The key is to notice how quickly the black king in each can get to g4 the key square to attack the g3 pawn (the key of white's king-side pawn chain).

In the first diagram, the black king is three spaces away from reaching g4. In the second, black's king is just two spaces away. And this is why only 1... Ke6 wins. In both diagrams immediately above, white is three moves away from f3 or f2 (the squares the black king must get to to guard the key g3 pawn). Thus, with 1... c2 the black king will reach its key square in the same amount of moves it takes the white king to get to its key square. The g3 pawn cannot be taken. With 1... Ke6 black reaches its key square one important tempo early. Thus, the g3 pawn can be taken by black. (See below).

AFTER THOUGHTS: dg, publisher of one of my absolute favorite chess blogs (http://boylston-chess-club.blogspot.com/), has noted that 1... Kd5 also leads to a pretty smooth victory for black. The concept is generally the same accept instead of racing the white king to the g3 pawn, black will now simply shoulder the white king away and seize up all of white's pawns. Excellent observation! I am embarassed I missed it!