HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-06 10:53:50 +08:00
Code Issues Packages Projects Releases Wiki Activity

Adaptive beta cut

Browse Source 
passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 197088 W: 51084 L: 50533 D: 95471
Ptnml(0-2): 547, 23201, 50577, 23592, 627
https://tests.stockfishchess.org/tests/view/680604d798cd372e3aea58fe

passed LTC
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 127950 W: 32719 L: 32214 D: 63017
Ptnml(0-2): 69, 13825, 35673, 14348, 60
https://tests.stockfishchess.org/tests/view/6805eae498cd372e3aea588a

closes https://github.com/official-stockfish/Stockfish/pull/6012

bench 1579003
This commit is contained in:
breatn
2025-04-22 18:54:04 +01:00
committed by Joost VandeVondele
parent 8b85290313
commit f590767b91
2 changed files with 14 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
AUTHORS
View File

@@ -34,6 +34,7 @@ Artem Solopiy (EntityFX)
Auguste Pop
Balazs Szilagyi
Balint Pfliegel
Baptiste Rech (breatn)
Ben Chaney (Chaneybenjamini)
Ben Koshy (BKSpurgeon)
Bill Henry (VoyagerOne)

14
src/search.cpp
View File

@@ -103,6 +103,18 @@ Value to_corrected_static_eval(const Value v, const int cv) {
return std::clamp(v + cv / 131072, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
}
int adaptive_probcut_margin(Depth depth) {
// Base margin
constexpr int base = 180;
// Approximate log2(depth) using a fast lookup table
static constexpr int logTable[32] = {0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4};
int logDepth = logTable[std::min(depth, 31)];
return base + logDepth * 60 + std::min(10, (depth - 16) * 2);
};
void update_correction_history(const Position& pos,
Stack* const ss,
Search::Worker& workerThread,
@@ -972,7 +984,7 @@ Value Search::Worker::search(
moves_loop: // When in check, search starts here
// Step 12. A small Probcut idea
probCutBeta = beta + 415;
probCutBeta = beta + adaptive_probcut_margin(depth);
if ((ttData.bound & BOUND_LOWER) && ttData.depth >= depth - 4 && ttData.value >= probCutBeta
&& !is_decisive(beta) && is_valid(ttData.value) && !is_decisive(ttData.value))
return probCutBeta;