14 March 2012

Opposition and Outflanking

A seemingly simple problem with five chess pieces, and for which I had a vague recollection of the solution, managed to occupy half an hour of my time on Monday. That half hour was spent solving and verifying, mostly by looking at a chess board with the position, and without moving the pieces. Another half hour was spent testing my solution against tChess Pro and Shredder on the iPad, then against Rybka 4 on the notebook.

The position is one of the blue diagrams in Dvoretsky's Endgame Manual (2003).

White to move

I have converted all of the blue diagrams from Dvoretsky's chapter on pawn endgames to flash cards for study and review. The answers are not on the cards, so I must keep a copy of Dvoretsky's text handy when I need an answer. I purchased the first edition of the book in paperback, and the second edition as a Kindle edition for access on my iPad. When I am on the road teaching chess in schools or giving private lessons in homes or cafes, I always have my deck of pawn endgame cards and the Kindle edition of Dvoretsky's Endgame Manual. With some students, we pick a card at random and try to solve it. Of the 48 cards, I instantly know the solution to 35-40. My plan (see "2012 New Year's Resolutions") is to know all 48.

On Monday, the diagram above was on the card that I randomly picked for my own training. I eventually solved it. I remembered that Dvoretsky had emphasized the importance of the f-file, and that grabbing the distant opposition with 1.Ke1 led only to a draw. After a few minutes, I remembered the first move 1.Kg2! Working out why this move was correct and the main variations took some time.

As it turned out, the key ideas were part of my teaching curriculum.

Elementary Instruction

In How to Reassess Your Chess, 3rd ed. (1993), Jeremy Silman presents an exercise that I find useful enough that I have incorporated it into my Scholastic Chess Awards curriculum. For the Bishop Award, the student must force his or her king to f8 or h8 against my efforts to prevent.

White to move

The process is simple when the student understands opposition and outflanking. Simply having the opposition is not enough. Silman explains, "the opposition is only a means to an end, not the end itself" (6).

This king vs. king exercise develops some of the requisite skills for prevailing over a skilled opponent in the next diagram.

White on move wins
Place the Black king on e7, and White must be the player on move for this position to be a win. After some practice and understanding, the student should become capable of winning this next position.

The player with the move wins

Training with Dvoretsky

Back to the problem that I wrestled with on Monday.* Swinging the king to the queenside to win Black's pawn was among the ideas that cropped up in my initial analysis of the position. But the immediate dash in that direction permits Black to defend successfully by maintaining the opposition in the battle for the key squares on the sixth rank. White cannot penetrate. But, some maneuvering on the kingside and then a transfer to the queenside works.

I found this key position in my analysis.

White to move

Reaching this position with Black to move draws. With White to move, the king runs around his pawns, using the a-file to outflank the Black king, and wins the Black pawn.

White to move

White must move to the a-file. These last two positions occurred in my battles with tChess Pro and Shredder, but Rybka kept its king on the eighth rank. Nevertheless, White's moves were the same in similar positions.

I was impressed by the need to play the whole board from the g-file to the a-file in order to win this game. On Monday, I posted my battle with Rybka 4 in a replayable format on my Chess.com blog.

*The problem from Dvoretsky's text appears in the Encyclopedia of Chess Endings as No. 846 in the Pawn Endings volume. Dvoretsky credits Jan Drtina as the composer, but in ECE it is attributed to František Dedrle.

1 comment:

  1. Quite interesting.
    I happen to study outflanking from Silmans book at the moment. Somehow these positions seem to have a whiff of magic around them. It's necessary to make the right moves second nature, I belief.