Increase the mg->eg gradient for the PawnlessFlank malus

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 325278fbc95acab4d559b94ae7a1787d2f8b0b9b..e8824b6bf4c6de59b6fb3cba1c50316436147e2d 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -82,7 +82,7 @@ namespace {
   // History and stats update bonus, based on depth
   int stat_bonus(Depth depth) {
     int d = depth / ONE_PLY;
-    return d > 17 ? 0 : 32 * d * d + 64 * d - 64;
+    return d > 17 ? 0 : 33 * d * d + 66 * d - 66;
   }
 
   // Skill structure is used to implement strength limit
@@ -935,8 +935,7 @@ moves_loop: // When in check, search starts from here
               int lmrDepth = std::max(newDepth - reduction<PvNode>(improving, depth, moveCount), DEPTH_ZERO) / ONE_PLY;
 
               // Countermoves based pruning (~20 Elo)
-              if (   lmrDepth < 4
-                  && (lmrDepth < 3 || ((ss - 1)->statScore > 0 && !PvNode))
+              if (   lmrDepth <= ((ss-1)->statScore > 0 ? 3 : 2)
                   && (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold
                   && (*contHist[1])[movedPiece][to_sq(move)] < CounterMovePruneThreshold)
                   continue;