Revert the heuristic introduced in #3184, by which we reduced more
the late sons of the root position after consecutive fail highs.
---
Before new net architecture:
STC:
LLR: 2.95 (-2.94,2.94) <-2.50,0.50>
Total: 226336 W: 20373 L: 20500 D: 185463
Ptnml(0-2): 755, 16087, 79595, 15992, 739
https://tests.stockfishchess.org/tests/view/
609dec205085663412d08e9d
LTC:
LLR: 2.93 (-2.94,2.94) <-2.50,0.50>
Total: 67432 W: 2411 L: 2375 D: 62646
Ptnml(0-2): 33, 1944, 29714, 2004, 21
https://tests.stockfishchess.org/tests/view/
609ee30f5085663412d08fc3
---
After new net architecture:
STC:
LLR: 2.95 (-2.94,2.94) <-2.50,0.50>
Total: 141752 W: 11591 L: 11617 D: 118544
Ptnml(0-2): 387, 9231, 51674, 9189, 395
https://tests.stockfishchess.org/tests/view/
60a4320ace8ea25a3ef03cfd
LTC:
LLR: 2.95 (-2.94,2.94) <-2.50,0.50>
Total: 294072 W: 9825 L: 9950 D: 274297
Ptnml(0-2): 121, 8610, 129681, 8521, 103
https://tests.stockfishchess.org/tests/view/
60a51b5ece8ea25a3ef03dcd
---
closes https://github.com/official-stockfish/Stockfish/pull/3490
Bench:
3752892
// Start with a small aspiration window and, in the case of a fail
// high/low, re-search with a bigger window until we don't fail
// high/low anymore.
- failedHighCnt = 0;
+ int failedHighCnt = 0;
while (true)
{
Depth adjustedDepth = std::max(1, rootDepth - failedHighCnt - searchAgainCounter);
if (ttCapture)
r++;
- // Increase reduction at root if failing high
- if (rootNode)
- r += thisThread->failedHighCnt * thisThread->failedHighCnt * moveCount / 512;
-
// Increase reduction for cut nodes (~3 Elo)
if (cutNode)
r += 2;
CapturePieceToHistory captureHistory;
ContinuationHistory continuationHistory[2][2];
Score contempt;
- int failedHighCnt;
};