Endgame: Centurini

Ok, so there's good news and bad news. Last night at the social chess, I lost two games in 10 minute blitz games (now I wonder why I bother to play such fast games) and I won a game against my opponent where we played without a clock.

My school starts next week and as expected, my chess club decides to commence their rated competition (just great) - which probably means that I can't really maintain a consistent rate of play.

I do notice that my endgame is starting to have an effect eg. have a look at this position. Is this a draw or a win for White? White to play.

This is the classic example of a position where Centurini's rules apply. There are 2 simple governing principles (and they only apply to B v B+P endgames):

1. The game is a draw if the black king can reach any square in front of the pawn that is not of the color of the bishop.

2. If the defending king is behind the pawn and the attacking king is near the pawn, the defender can draw only if his king is attacking the pawn, he has the opposition, and his bishop can move on two diagonals that have at least two squares each.

Now this is where Black runs into trouble in this game here. Because this is a Knight's pawn, Black's bishop cannot move on 2 diagonals with more than 2 squares each (see the highlighted green squares - Black is in trouble because while the a8-h1 diagonal is fine, the other diagonal a6-c8 is only 3 squares but 1 of them is crucially held by the White king - b7) and Black will gradually be eased out by White who will start to move his bishop to the vital square b7 via f5-c8-b7 (to drive off the Black Bishop off the a8-h1 diagonal) and when Black's bishop goes to a6 (only position possible to stop the pawn from advancing); sacrificing the White bishop via the following moves b7-g2-f1 ensures the pawn queens, reaching a winning Q v B endgame.