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 :-)
STC:
https://tests.stockfishchess.org/tests/view/602f03d07f517a561bc49d40
LLR: 2.94 (-2.94,2.94) {-0.25,1.25}
Total: 67664 W: 6252 L: 6035 D: 55377
Ptnml(0-2): 256, 4799, 23527, 4972, 278
LTC:
https://tests.stockfishchess.org/tests/view/602f41697f517a561bc49d5a
LLR: 2.96 (-2.94,2.94) {0.25,1.25}
Total: 26256 W: 1034 L: 906 D: 24316
Ptnml(0-2): 10, 804, 11377, 922, 15
Closes https://github.com/official-stockfish/Stockfish/pull/3363
Bench: 3957653