Chess strategy consists of setting and achieving long term goals during the game, chess strategy is concered with the evaluation of chess positions and with setting up goals for long term plans for the future play.
In chess, tactics in general concentrate on short-term actions, so short that they can be calculated in advance by a human player or by a computer. Simple one-move or two-move tactical actions - threats, exchanges of material, double attacks etc. can be combined into more complicated variants, tactical maneuvers, often forced from one side or from both.
Because of different strategic and tactical patterns, a game of chess is usually divided into three distinct phases: opening, usually the first 10 to 25 moves, when players develop their armies and set up the stage for the coming battle; middlegame, the developed phase of the game; and endgame, when most of the pieces are gone and kings start to take an active part in the struggle.
The most basic step in evaluating a position is to count the total value of pieces of both sides. The point values used for this purpose are based on experience; usually pawns are considered worth one point, knights and bishops about three points each, rooks about five points, and queens about nine points.
In the endgame, the king is generally more powerful than a bishop or knight but less powerful than a rook, thus it is sometimes assigned a fighting value of four points. These basic values are then modified by other factors like position of the piece, coordination between pieces, or type of position.