Middlegame

The central stage of a game. Both sides still have comparatively large forces on the board. The middlegame is also marked by the passive role of the kings and by threats arising in the sectors where they stand.

This definition is formal to a degree, since you cannot always draw a sharp line where the opening turns into the middlegame, or the middlegame into the endgame. This leads many theorists to see two further intermediate stages in a game of chess: the transition from the opening to the middlegame and from the middlegame to the endgame.

Where the opening's tasks are to seize the center and mobilize the pieces quickly, in the middlegame the center has already taken definite shape, and each side's plans grow out of what the mobilized pieces can do. The opening and the middlegame are closely linked, and the middlegame plan is a logical continuation of the opening line, merging with it into a single idea. The same link can be seen between the middlegame and the endgame. Formally, the middlegame ends the moment the kings are no longer in danger and turn from passive pieces into active ones.

Theory of the middlegame

The theory of the middlegame began to develop later than opening theory and endgame theory. Philidor is generally credited with the first attempt to formulate some principles of the middlegame. His theory, however, which held that the basis of every position is pawn structure, was far too one-sided. Petrov was the first to criticize the extremes of Philidor's theory.

Although many outstanding players of the 19th century, Morphy above all, published no works on middlegame theory, their play contributed a great deal to a proper understanding of middlegame ideas. Steinitz formulated the theory of the middlegame most fully and systematically. But his views contained many dogmatic claims. The fight against such claims, led by Chigorin, deepened the proper understanding of how to play the middlegame.

Later, major contributions to the theory of the middlegame came from Tarrasch, Lasker, Capablanca, Rubinstein, Réti, Nimzowitsch, Alekhine, Euwe, and then the Soviet players.