Chess - Programming - Hash Functions

Hash functions convert chess positions into an almost unique, scalar signature, allowing fast index calculation as well as space saving verification of stored positions.

Common Hash Functions are:

NOTE: They use fast hash functions, to provide hash keys or signatures as a kind of Gödel number of chess positions, today typically 64-bit wide.

  • They are updated incrementally during make and unmake move by either own-inverse exclusive or or by addition versus subtraction.

References

https://www.ics.uci.edu/~eppstein/180a/970424.html