VVLTC search tune
Search parameters were tuned at 60+0.6 8-thread.
Link to the tuning attempt: https://tests.stockfishchess.org/tests/view/65b84e8dc865510db0276030
The most significant change is the triple extension parameter, from 200 to 78. This presumably improves scaling.
Additionally, the value < singularBeta - 2 condition for double extensions was removed.
This can simply be considered a parameter tweak from 2 to 0.
Passed VVLTC: https://tests.stockfishchess.org/tests/view/65baec69c865510db0278f19
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 26136 W: 6564 L: 6305 D: 13267
Ptnml(0-2): 2, 2413, 7977, 2676, 0
Passed VVLTC vs passed PR #5027: https://tests.stockfishchess.org/tests/view/65bc2adfc865510db027a561
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 52968 W: 13372 L: 13046 D: 26550
Ptnml(0-2): 4, 4944, 16265, 5264, 7
STC Elo estimate: https://tests.stockfishchess.org/tests/view/65be5514c865510db027cbc5
closes https://github.com/official-stockfish/Stockfish/pull/5029
Bench: 1478189