27.09.2004 S.Klimov “Disturbance of material balance” - 2

The second part of the article about the disturbance of material correlation of forces is devoted to positional sacrifice of exchange.

Playing in such positions has a number of peculiarities in comparison with sacrifice of a pawn or a piece, that was analyzed in the first part.

The main distinction is in the diversity of the material. Compensation changes depending on the type of the position, quantity of pawns, presence of open lines (files and diagonals), mobility of pawn structure etc.

In the article the classification of sacrifices according to compensative factor is given, the typical positions in which compensation may be considered to be sufficient and the methods of the struggle for the opposite side are pointed out.

Kinds of sacrifice.

Although in the real game different factors, which compensate the lack of the material are interlaced with one another and transform into one another, it is possible to point out some main kinds of the sacrifices of exchange. There are about five of them:

a) a sacrifice that destroys the pawn structure (among these are opening and middlegame sacrifices of a Rook for a Knight c3/f3 or c6/f6, depending on the colour of pieces)

b) a sacrifice that forms a strong pawn structure (usually a pair of pаssed pawns or a defended passed pawn in the centre)

c) for the moving of passed pawns

d) for the development in rapid attack

e) for piece domination.

In the last, the most important kind of sacrifice exchange is compensated by superiority of a light piece over a Rook in case of absence (or unimportance) of open files at a chess board, by bad position of opponent's pieces and by possession of a complex of the squares of one colour.

There are several typical middlegame structures, in which light piece is not weaker than a Rook. The examples of them are: the pawn "a" and the Bishop at the large diagonal in Grunfeld, Bishops and a passed pawn (especially a far advanced) in a position of the open type, the Knight e6 and the pawn d5 in the King's Indian structure, blockade of white squares for exchange in the French defense, sacrifice of exchange at a1 (a8) for the Bishop that was developed in fianchetto with subsequent attack on the weakened white squares etc.

The main methods of opponent’s playing are:

- simplification of position and exchange of attacking pieces

- closing of the line of attack by opponent's pieces

- using of the Rook's force (opening of files, frontal attack on the opponent's weak points or invasion of heavy pieces).