Pawn clean up

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 1fc0bf1e6c6455ea470ad7047d80c8a5d2e85ef5..222be393be5c915834429b5302cfd5de164bf4fd 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1114,6 +1114,13 @@ moves_loop: // When in check, search starts from here
                              + (*contHist[3])[movedPiece][to_sq(move)]
                              - 4000;
 
+              // Reset statScore to zero if negative and most stats shows >= 0
+              if (    ss->statScore < 0
+                  && (*contHist[0])[movedPiece][to_sq(move)] >= 0
+                  && (*contHist[1])[movedPiece][to_sq(move)] >= 0
+                  && thisThread->mainHistory[us][from_to(move)] >= 0)
+                  ss->statScore = 0;
+
               // Decrease/increase reduction by comparing opponent's stat score (~10 Elo)
               if (ss->statScore >= 0 && (ss-1)->statScore < 0)
                   r -= ONE_PLY;
@@ -1145,7 +1152,7 @@ moves_loop: // When in check, search starts from here
                                         : -stat_bonus(newDepth);
 
               if (move == ss->killers[0])
-                 bonus += bonus / 4;
+                  bonus += bonus / 4;
 
               update_continuation_histories(ss, movedPiece, to_sq(move), bonus);
           }