Fundamentals of Chess tactics

A tactical puzzle from Lucena's 1497 book

From a match between Mikhail Botvinnik and Mikhail Yudovich.^[6] After sacrificing a piece to expose Black's king, Botvinnik played 1. Bh5+ and Yudovich resigned as mate is inevitable, e.g. 1...Kxh5 2.Ng3+ Kh4 3.Qe4+ Rf4 4.Qxf4#, or 1...Kh7 2.Nf6+ double check Kh8 3.Qh7#.

In chess, tactics in general concentrate on short-term actions – so short-term that they can be calculated in advance by a human player or by a computer. The possible depth of calculation depends on the player's ability or speed of the processor. In quiet positions with many possibilities on both sides, a deep calculation is not possible, while in "tactical" positions with a limited number of forced variations where much less than the best move would lose quickly, strong players can calculate very long sequences of moves.

Simple one-move or two-move tactical actions – threats, exchanges of material, double attacks etc. – can be combined into more complicated combinations, sequences of tactical maneuvers that are often forced from the point of view of one or both players.^[7] Theoreticians described many elementary tactical methods and typical maneuvers, for example pins, forks, skewers, discovered attacks (especially discovered checks), zwischenzugs, deflections, decoys, sacrifices, underminings, overloadings, and interferences.^[8]

A forced variation that involves a sacrifice and usually results in a tangible gain is called a combination.^[7] Brilliant combinations – such as those in the Immortal Game – are considered beautiful and are admired by chess lovers. A common type of chess exercise, aimed at developing players' skills, is showing players a position where a decisive combination is available and challenging them to find it.