Wednesday, November 24, 2010

Some Endgame Lessons

Prospect split with the Groves last week, losing a tough match to undefeated Buffalo Grove 42.5-25.5 on Tuesday and beating Elk Grove on Thursday 56.5-11.5. With some better endgame play, the Buffalo Grove match could have been much closer.

Endgame Lesson #1: King and Rook v. King and Pawn

The following position (more or less) occurred on 4th Board with Nick Martin playing white against Buffalo Grove's Matt Wiewel.

This should be a fairly easy win for White. Black will be compelled to give up his for White's d-pawn and White's king and rook should be able to round up the remaining Black pawns easily. However, it is possible to go wrong, so it is worthwhile considering an even more basic position.

The only way for White to win here is with 1.Rb5 cutting off the Black king from supporting the pawn. 1...f3 2.Rb3 f2 3.Rf3 f1=Q 4.Rxf1 and hopefully White knows how to mate with a king and rook. It is vital that White cut off the Black king immediately because the game is drawn if Black's king and pawn are another square farther down the board.

Now 1.Rb4 doesn't do the trick. After 1...f2, White is forced to play 2.Rb1 Kb4 3. Rf1 Kb3 and the game is drawn because White will be forced to trade his rook for the Black pawn.

Returning to the position from Martin-Wiewel, the easiest way for White to avoid a position where his rook might have trouble coping with the Black king and pawns is to get the White king into the action. Unfortunately, White tried to win the game without his king. 1.Ke8?! Heading the wrong direction. After 1.Ke6 Ra8 2.d8=Q Rxd8 3.Rxd8, the White king would have been two squares closer to the action than it was in the game after 1...Ra8+ 2.d8=Q Rxd8+ 3. Kxd8 Kf6. Still if White gets his king moving the win should be fairly easy. 4.Rf2?! Still on the wrong track. 4...Kf5 5.h3??. This was White's last chance, he still could have won with 5.Ke7 g4 6. Kd6 f3 7.Kd5 Kf4 8. Kd4 g3 9.hxg3+ Kxg3 10.Kf3. Now the win is no longer there after 5...g4 6.hxg4 Kxg4

The White king is too far away. The rook is a wonderfully powerful piece, but it cannot handle the combined king and pawn by itself. If it cannot cut off the king before the pawn has advanced too far, the rook must have the king's help to cope.

Endgame Lesson #2: Defending Rook and Pawns v. Rook and Pawns.

There is an old aphorism in chess that goes "All rook endings are drawn." This is obviously not true, but rook endings often offer unexpected drawing possibilities. Before considering the ending that arose between Michael Monsen and Matt Wiewel on 5th Board in the Buffalo Grove match, let's start with another basic position.

This position is drawn as long as White toggles his king between g2 and h2 because the Black rook is stuck in front of its own pawn. If White plays 1.Kg3, Black wins with 1...Rg1+ 2.Kf2 a1=Q. If White plays 1.Kf2, Black wins with 1...Rh2 2.Rxa2 Rh2+ 3.Kg3 Rxa2. However, after 1.Kh2, the Black rook cannot escape without dropping the pawn. If Black tries to bring his king over to help, the White rook will check it away.

Black has an extra pawn, but as in the previous diagram, his rook is defending the pawn from in front and the Black king is in no position to relieve the rook of its defensive chores. White panicked with 43.Rd3?? and was helpless against Black's extra pawn after the exchange of rooks . However, if White could have gotten his rook behind Black's passed pawn, I think he should have had pretty good drawing chances. 43. Rd5! looks very solid. After 45...a4 Ra5, it is hard to see how Black is going to improve his position as his king is tied to the defense of the f-pawn and the rook is tied to the a-pawn. If Black should try to bring his king over to support the a-pawn, White can bring his king over to defend and leave the rook to defend pawns on the other side.

No comments:

Post a Comment