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Pawn Formations

Chess grandmasters often say that pawns are the soul of the game. While this is far from obvious to the neophyte, the fact that great players often resign over the loss of a single pawn clearly indicates that they mean it!

Chess literature mentions several types of pawn features, some valuable, some negative. My program looks at the following:

• Doubled or tripled pawns. Two or more pawns of the same color on the same file are usually bad, because they hinder each other's movement.

• Pawn rams. Two opposing pawns "butting heads" and blocking each other's forward movement constitute an annoying obstacle.

• Passed pawns. Pawns which have advanced so far that they can no longer be attacked or rammed by enemy pawns are very strong, because they threaten to reach the back rank and achieve promotion.

• Isolated pawns. A pawn which has no friendly pawns on either side is vulnerable to attack and should seek protection.

• Eight pawns. Having too many pawns on the board restricts mobility; opening at least one file for rook movement is a good idea.

A final note on pawn formations: a passed pawn is extremely dangerous if it has a rook standing behind it, because any piece that would capture the pawn is dead meat. My program therefore scores a passed pawn as even more valuable if there is a rook on the same file and behind the pawn.

King Safety and Tropism

We have already touched on king safety earlier: in the opening and middle game, protecting the king is paramount, and castling is the best way to do it.

However, in the endgame, most of the pieces on both sides are gone, and the king suddenly becomes one of your most effective offensive assets! Leaving him behind a wall of pawns is a waste of resources.

As for "tropism", it is a measure of how easy it is for a piece to attack the opposing king, and is usually measured in terms of distance. The exact rules used to compute tropism vary by piece type, but they all amount to this: the closer you are to the opposing king, the more pressure you put on it.

Next : Picking the Right Weights