Phases of the game
A game of chess is divided into three distinct phases, known as the Opening, the Middlegame, and the Endgame.
The opening in chess covers the first 10 to 15 moves of the game, in which both players are moving their pieces from their starting positions to take up active posts ready to do battle in the middlegame.
The middlegame in chess is the portion of the game in between the opening and the endgame, though there is no clear line between the opening and middlegame, and between the middlegame and endgame. But as a general rule it occurs once the pieces have been deployed from their starting squares and the kings have castled to safety.
This is the stage of the game when most of the pieces have been captured and only a few remain. The final stage of a chess game.