High Quality Content by WIKIPEDIA articles! Zobrist hashing (also referred to as Zobrist keys or Zobrist signatures ) is a hash function construction used in computer programs that play abstract board games, such as chess and Go, to implement transposition tables, a special kind of hash table that is indexed by a board position. ZObrist hashing is named for its inventor, Albert Zobrist.ZObrist hashing starts by randomly generating bitstrings for each possible element of a board game. GIven a certain board position, it breaks up the board into independent components, finds out what state each component is in, and combines the bitstrings representing those elements together using bitwise XOR. IF the bitstrings are long enough, different board positions will almost certainly hash to different values; however longer bitstrings require proportionally more computer resources to manipulate. MAny game engines store only the hash values in the transposition table, omitting the position information itself entirely to reduce memory usage, and assuming that hash collisions will not occur, or will not greatly influence the results of the table if they do.