Combo of various parameter tweaks

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index ed5dd6c2c7ad5aab3e39b26cb038833c3a6b58d2..b400b8f8b0c4c409d4c004e6047f12468e8d2959 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -793,7 +793,7 @@ namespace {
         && (ss-1)->statScore < 23767
         &&  eval >= beta
         &&  eval >= ss->staticEval
-        &&  ss->staticEval >= beta - 20 * depth - 22 * improving + 168 * ss->ttPv + 159
+        &&  ss->staticEval >= beta - 20 * depth - 22 * improving + 168 * ss->ttPv + 177
         && !excludedMove
         &&  pos.non_pawn_material(us)
         && (ss->ply >= thisThread->nmpMinPly || us != thisThread->nmpColor))
@@ -903,12 +903,17 @@ namespace {
          ss->ttPv = ttPv;
     }
 
-    // Step 10. If the position is not in TT, decrease depth by 2
+    // Step 10. If the position is not in TT, decrease depth by 2 or 1 depending on node type
     if (   PvNode
         && depth >= 6
         && !ttMove)
         depth -= 2;
 
+    if (   cutNode
+        && depth >= 9
+        && !ttMove)
+        depth--;
+
 moves_loop: // When in check, search starts here
 
     ttCapture = ttMove && pos.capture_or_promotion(ttMove);
@@ -1026,8 +1031,8 @@ moves_loop: // When in check, search starts here
 
               // Futility pruning: parent node (~5 Elo)
               if (   !ss->inCheck
-                  && lmrDepth < 7
-                  && ss->staticEval + 174 + 157 * lmrDepth <= alpha)
+                  && lmrDepth < 8
+                  && ss->staticEval + 172 + 145 * lmrDepth <= alpha)
                   continue;
 
               // Prune moves with negative SEE (~20 Elo)
@@ -1052,7 +1057,7 @@ moves_loop: // When in check, search starts here
           && (tte->bound() & BOUND_LOWER)
           &&  tte->depth() >= depth - 3)
       {
-          Value singularBeta = ttValue - 2 * depth;
+          Value singularBeta = ttValue - 3 * depth;
           Depth singularDepth = (depth - 1) / 2;
 
           ss->excludedMove = move;
@@ -1096,8 +1101,8 @@ moves_loop: // When in check, search starts here
       }
 
       // Capture extensions for PvNodes and cutNodes
-      else if (   (PvNode || cutNode) 
-               && captureOrPromotion 
+      else if (   (PvNode || cutNode)
+               && captureOrPromotion
                && moveCount != 1)
           extension = 1;