The Middle Game

The middlegame in chess refers to the portion of the game that happens immediately after the opening (usually the first move after the procession of moves that make up a standard opening) and blends somewhat with the endgame. During this time, players will attempt to strengthen their positions while weakening their opponent's, both by careful arrangement of the pieces for prepared attacks and defenses and by whittling away at their opponent's numbers.

The demarcation between the opening and middlegame, and the middlegame and endgame, is not always clear. Compared to the opening, both players will usually have completed the development of all or most pieces (except the king which will usually have been brought to relative safety.) Compared to the endgame, the middlegame has several pieces on the board, and the strength of these forces makes the kings' roles rather defensive. Factors such as control of the centre are more important in the middlegame than the endgame. There are differing opinions and criteria for when the middlegame ends and the endgame starts.

Theory on the middlegame is less developed than the opening or endgames. Since middlegame positions from game to game are unique, memorization of theoretical variations is not possible as it is in the opening. Likewise, there are usually too many pieces on the board for theoretical positions to be analyzed as can be done in the endgame.

 

The Aims of Middle Game

The Middle Game in Chess by Reuben Fine lists three major factors in the middlegame: king safety, force (material) and mobility, although not all of these factors are of equal importance. If king safety is a serious issue, a well-executed attack on the king can render other considerations, including material advantages, irrelevant.

Material is another important consideration, Fine notes that with all other things equal, any material advantage will usually be decisive. According to Fine, a material advantage will usually not give a direct mating attack unless the advantage is very large (a rook or more), rather it can be used as a means of gaining more material and a decisive endgame advantage.

The issue of mobility is ensuring that the pieces have a wide scope of action and targets to focus on. The concept is largely strategic  in nature, and involves concepts as space, pawn weaknesses (since weak pawns can compel pieces to defensive duties, reducing their mobility), and securing outposts for the pieces.

The strategy required for middlegame play varies considerably. Some middlegame positions feature closed centers featuring maneuvering behind the lines, while other middlegames are wide open, where both players attempt to gain the initiative. Dan Heisman noted three features which can seriously alter the way the middlegame is played.

1. First, if the kings are castled on opposite wings, and queens remain on the board, the position can be very violent, with both players aiming to assault the enemy king. Material considerations are often secondary to pursuing the attack, and it can even be advantageous to lose pawns in front of the enemy king in order to open up lines for the rooks and queen.
2. Second, positions where the pawn structure is static and locked, can also feature mutual attacks, since players often elect to play on the side where they have more space (playing on the side of the board in which their pawns are pointing). Time is often less of a concern in such middlegames, allowing lengthy maneuvers. Both players need to be on the lookout for pawn breaks, and the possibility of taking advantage of the open files which may arise from them.
   
3. Third, if one player has an overwhelming material advantage and is clearly winning, the stronger player can usually afford to violate several of the normal middlegame principles in order to trade down to an endgame. For example, trading queens even at the cost of a ruined pawn structure may be a viable option.
   

 

Transition to the Endgame

Not all games reach the endgame, since an attack on the king, or a combination leading to large material gains can end the game while it is still in the middlegame. At other times, an advantage needs to be pursued in the endgame, and learning how to make favorable exchanges leading to a favorable endgame is an important skill.

The last thing that happens in the middlegame is the setup for endgame. Since many endgames involve the promotion of a pawn, it is usually good to keep that in mind when making trades during the middlegame.

As capablanca said, one can study opening and endgame individually but the middlegame must be studied keeping the endgame in mind. And the goal of middlegame is to reach a winning endgame.