Latest abrok Development Version Febuary 9th (SF The gift that keeps on giving

!! latest version !!


Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Michael Chaly
Date: Wed Feb 9 17:17:00 2022 +0100
Timestamp: 1644423420

Big search tuning

Most credits for this patch should go to @candirufish.
Based on his big search tuning (1M games at 20+0.1s)

https://tests.stockfishchess.org/tests/view/61fc7a6ed508ec6a1c9f4b7d

with some hand polishing on top of it, which includes :

a) correcting trend sigmoid - for some reason original tuning resulted in it being negative. This heuristic was proven to be worth some elo for years so reversing it sign is probably some random artefact;
b) remove changes to continuation history based pruning - this heuristic historically was really good at providing green STCs and then failing at LTC miserably if we tried to make it more strict, original tuning was done at short time control and thus it became more strict - which doesn't scale to longer time controls;
c) remove changes to improvement - not really indended :).

passed STC
https://tests.stockfishchess.org/tests/view/6203526e88ae2c84271c2ee2
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 16840 W: 4604 L: 4363 D: 7873 Elo +4.97
Ptnml(0-2): 82, 1780, 4449, 2033, 76

passed LTC
https://tests.stockfishchess.org/tests/view/620376e888ae2c84271c35d4
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 17232 W: 4771 L: 4542 D: 7919 Elo +4.62
Ptnml(0-2): 14, 1655, 5048, 1886, 13

closes https://github.com/official-stockfish/Stockfish/pull/3926

bench 5030992
see source