Change extra ply LMR condition to: cmh <= 0 && hist < 0

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 2149df2ba8fe340326ac45be06440f981e7d8826..636b1db404e4424721e42473108cb36869aaa21b 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -960,9 +960,8 @@ moves_loop: // When in check and at SpNode search starts from here
           ss->reduction = reduction<PvNode>(improving, depth, moveCount);
 
           if (   (!PvNode && cutNode)
-              || (  History[pos.piece_on(to_sq(move))][to_sq(move)]
-                  + CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq]
-                                       [pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO))
+              || (   History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO
+                  && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq][pos.piece_on(to_sq(move))][to_sq(move)] <= VALUE_ZERO))
               ss->reduction += ONE_PLY;
 
           if (move == countermove)