The middlegame is the portion of the game that directly follows the opening and forms the prelude to the endgame. You must strengthen your position and in doing so undermine that of your opponent.
Attention should be both given to the orchestration of positional superiority and the possibility of profit by way of two to three move tactical maneuvers.
The opening is generally thought to be over when the minor pieces have been developed, both sides have castled and the Rooks and Queens have been stationed at deep positions behind the battle lines.
The dividing line between the middlegame and the endgame is when the pieces have mostly been removed. So the
middlegame is the contest for supremacy leading into the endgame.
The middlegame is the contest for supremacy