Editing Transposition table (section)

==Related techniques==
* Similar techniques can be used to cache evaluations of certain features of a position. For example, a ''pawn hash table'' can be used to store an evaluation of the [[pawn (chess)|pawn]] structures in a position. Since the number of pawn positions examined is generally much smaller than the total number of positions searched, the pawn hash table has a very high [[Cache (computing)#Operation|hit rate]], allowing a program to spend more time on sophisticated pawn evaluations because they are reused many times.
* A ''refutation table'' can be used to store sequences of moves from the root node to leaf nodes. This includes the [[principal variation]] and responses to other lines showing that they are inferior. Refutation tables were sometimes used instead of transposition tables in the earlier years of computer chess, when memory was more limited. Some modern chess programs use refutation tables in addition to transposition tables for move ordering, while most do not use them at all.
*Static bitmaps of the possible moves of each type of piece on each space of the board can be cached at program initialization, so that the legal moves of a piece (or together, all legal moves for move generation) can be retrieved with a single memory load instead of having to be serially enumerated. These are commonly used in bitboard implementations.