The idea, as mentioned by Peregrine is that in our standard code, if no best move found after searching all moves, we give a bonus to the previous move that caused the fail high. So in razoring we assume no bestmove will be found so we might as well do the same.
Author: Michael Chaly Date: Fri Oct 27 17:24:25 2023 +0200 Timestamp: 1698420265
Introduce pawn structure based history
Original idea by Seer chess engine https://github.com/connormcmonigle/seer-nnue, coding done by @Disservin, code refactoring done by @locutus2 to match the style of other histories.
This patch introduces pawn structure based history, which assings moves values based on last digits of pawn structure hash and piece type of moved piece and landing square of the move. Idea is that good places for pieces are quite often determined by pawn structure of position. Used in 3 different places - sorting of quiet moves, sorting of quiet check evasions and in history based pruning in search.
