Based on recent improvement of futility pruning by @locutus2 : we lower
the futility margin to apply it for more nodes but as a compensation
we also lower the history threshold to apply it to less nodes. Further
work in tweaking constants can always be done - numbers are guessed
"by hand" and are not results of some tuning, maybe there is some more
Elo to squeeze from this part of code.
Passed STC
LLR: 2.98 (-2.94,2.94) {-1.00,3.00}
Total: 15300 W: 3081 L: 2936 D: 9283
Ptnml(0-2): 260, 1816, 3382, 1900, 290
http://tests.stockfishchess.org/tests/view/
5e18da3b27dab692fcf9a158
Passed LTC
LLR: 2.94 (-2.94,2.94) {0.00,2.00}
Total: 108670 W: 14509 L: 14070 D: 80091
Ptnml(0-2): 813, 10259, 31736, 10665, 831
http://tests.stockfishchess.org/tests/view/
5e18fc9627dab692fcf9a180
Bench:
4643972
Vince Negri (cuddlestmonkey)
-# Additionally, we acknowledge the authors and maintainer of fishtest,
+# Additionally, we acknowledge the authors and maintainers of fishtest,
# an amazing and essential framework for the development of Stockfish!
#
# https://github.com/glinscott/fishtest/blob/master/AUTHORS
// Futility pruning: parent node (~5 Elo)
if ( lmrDepth < 6
&& !inCheck
- && ss->staticEval + 255 + 182 * lmrDepth <= alpha
+ && ss->staticEval + 235 + 172 * lmrDepth <= alpha
&& thisThread->mainHistory[us][from_to(move)]
+ (*contHist[0])[movedPiece][to_sq(move)]
+ (*contHist[1])[movedPiece][to_sq(move)]
- + (*contHist[3])[movedPiece][to_sq(move)] < 30000)
+ + (*contHist[3])[movedPiece][to_sq(move)] < 25000)
continue;
// Prune moves with negative SEE (~20 Elo)