Author: Vizvezdenec Date: Sat Feb 20 22:49:39 2021 +0100 Timestamp: 1613857779
Introduce ProbCut for check evasions
The idea of this patch can be described as follows: if we are in check and the transposition table move is a capture that returns a value far above beta, we can assume that the opponent just blundered a piece by giving check, and we return the transposition table value. This is similar to the usual probCut logic for quiet moves, but with a different threshold.
The committed version has an additional fix to never return unproven wins in the tablebase range or the mate range. This fix passed tests for non- regression at STC and LTC:
Author: Vizvezdenec Date: Sat Feb 20 22:22:07 2021 +0100 Timestamp: 1613856127
Tune search parameters (with Unai Corzo)
The values used in this patch are taken from a SPSA parameter tuning session originated by Unai Corzo (@unaiic), but the final difference of his tune was multiplied x2 by hand. Most of the credits should go to him :-)
