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Simplification for countermoves based pruning

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Simplify away two extra conditions in countermoves based pruning.
These conditions (both of them) were introduced quite a long time ago
via speculative LTCs and seem to no longer bring any benefit.

passed STC
https://tests.stockfishchess.org/tests/view/609e81f35085663412d08f31
LLR: 2.96 (-2.94,2.94) <-2.50,0.50>
Total: 28488 W: 2487 L: 2382 D: 23619
Ptnml(0-2): 87, 1919, 10123, 2032, 83

passed LTC
https://tests.stockfishchess.org/tests/view/609e9c085085663412d08f59
LLR: 2.95 (-2.94,2.94) <-2.50,0.50>
Total: 33176 W: 1219 L: 1155 D: 30802
Ptnml(0-2): 13, 1036, 14423, 1106, 10

closes https://github.com/official-stockfish/Stockfish/pull/3468

Bench: 4749514
This commit is contained in:
Vizvezdenec
2021-05-15 00:55:45 +03:00
committed by Stéphane Nicolet
parent c82f6f56a6
commit 61e1c66b7c
1 changed files with 1 additions and 1 deletions
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2
src/search.cpp
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@@ -1026,7 +1026,7 @@ moves_loop: // When in check, search starts from here
else else
{ {
// Countermoves based pruning (~20 Elo) // Countermoves based pruning (~20 Elo)
if ( lmrDepth < 4 + ((ss-1)->statScore > 0 || (ss-1)->moveCount == 1) if ( lmrDepth < 4
&& (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold && (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold
&& (*contHist[1])[movedPiece][to_sq(move)] < CounterMovePruneThreshold) && (*contHist[1])[movedPiece][to_sq(move)] < CounterMovePruneThreshold)
continue; continue;