Cache of previously seen positions, and associated evaluations in a game tree
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A transposition table is a cache of previously seen positions, and associated evaluations, in a game tree generated by a computer game playing program. If a position recurs via a different sequence of moves, the value of the position is retrieved from the table, avoiding re-searching the game tree below that position. Transposition tables are primarily useful in perfect-information games (where the entire state of the game is known to all players at all times). The usage of transposition tables is essentially memoization applied to the tree search and is a form of dynamic programming.
Transposition tables are typically implemented as hash tables encoding the current board position as the hash index. The number of possible positions that may occur in a game tree is an exponential function of depth of search, and can be thousands to millions or even much greater. Transposition tables may therefore consume most of available system memory and are usually most of the memory footprint of game playing programs.
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A transpositiontable is a cache of previously seen positions, and associated evaluations, in a game tree generated by a computer game playing program...
Look up transposition in Wiktionary, the free dictionary. Transposition may refer to: Transposition (mathematics), a permutation which exchanges two elements...
color) is alphaOrig := α (* TranspositionTable Lookup; node is the lookup key for ttEntry *) ttEntry := transpositionTableLookup(node) if ttEntry is valid...
modestly with processor speed, but sufficient memory to hold a large transpositiontable (up to several gigabytes or more) is more important to playing strength...
abstract board games, such as chess and Go, to implement transpositiontables, a special kind of hash table that is indexed by a board position and used to avoid...
Cryptographic hash function Distributed hash table Identicon Low-discrepancy sequence Transpositiontable This is useful in cases where keys are devised...
tree search Negamax Negascout Sion's minimax theorem Tit for Tat Transpositiontable Wald's maximin model Bacchus, Barua (January 2013). Provincial Healthcare...
use a form of NegaScout in their search. Most chess engines use a transpositiontable in which the relevant part of the search tree is stored. This part...
cipher was a fractionating transposition cipher which combined a modified Polybius square with a single columnar transposition. The cipher is named after...
code can be used to encrypt text with the affine cipher: # Prints a transpositiontable for an affine cipher. def affine(a: int, b: int, s: str): import...
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In logic and mathematics, contraposition, or transposition, refers to the inference of going from a conditional statement into its logically equivalent...
implementing directive were transposed in full and on time, with minor exceptions. The European Commission has published a transpositiontable linking to lists of...
deepening approach. In order to quickly store a full-sized Go board in a transpositiontable, a hashing technique for mathematically summarizing is generally...
used to reduce the size of the searched tree: good move ordering, transpositiontable and selective Search. To speed up the search on machines with multiple...
by Matthieu Leschemelle. The name CuckooChess comes due that the transpositiontable is based on Cuckoo hashing. Android app based chess gaming app Droidfish...
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