Make use of asymmetric SEE

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index e246512e985bbccff13c91c307454f680dd24356..ab34673463c57286d7ec4047a46755d6fc24701e 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -876,7 +876,7 @@ split_point_start: // At split points actual search starts from here
           // but fixing this made program slightly weaker.
           Depth predictedDepth = newDepth - reduction<PvNode>(depth, moveCount);
           futilityValue =  ss->staticEval + ss->evalMargin + futility_margin(predictedDepth, moveCount)
-                         + 2 * Gain[pos.piece_moved(move)][to_sq(move)];
+                         + Gain[pos.piece_moved(move)][to_sq(move)];
 
           if (futilityValue < beta)
           {
@@ -1228,7 +1228,7 @@ split_point_start: // At split points actual search starts from here
           // Prune moves with negative or equal SEE
           if (   futilityBase < beta
               && depth < DEPTH_ZERO
-              && pos.see(move) <= 0)
+              && pos.see_asymm(move, beta - futilityBase) <= 0)
           {
               bestValue = std::max(bestValue, futilityBase);
               continue;