X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=0d7575aa5248433ae0d6e788ea40d8267b288cb8;hb=e404a7d97c94890dda18ca3a16cfd15b5a7ef235;hp=c48b74bcc76ddc0761cdb9c44d961dffa4b0f2c0;hpb=dabaf2220fe0c77400a5f71a91952f510e6a126b;p=stockfish

diff --git a/src/search.cpp b/src/search.cpp
index c48b74bc..0d7575aa 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -801,7 +801,7 @@ namespace {
         assert(eval - beta >= 0);
 
         // Null move dynamic reduction based on depth and value
-        Depth R = (1090 + 81 * depth) / 256 + std::min(int(eval - beta) / 205, 3);
+        Depth R = std::min(int(eval - beta) / 205, 3) + depth / 3 + 4;
 
         ss->currentMove = MOVE_NULL;
         ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0];
@@ -1018,9 +1018,10 @@ moves_loop: // When in check, search starts here
           else
           {
               // Continuation history based pruning (~20 Elo)
-              if (   lmrDepth < 5
-                  && (*contHist[0])[movedPiece][to_sq(move)] < 23 - 23 * depth * depth
-                  && (*contHist[1])[movedPiece][to_sq(move)] < 23 - 23 * depth * depth)
+              if (lmrDepth < 5
+                  && (*contHist[0])[movedPiece][to_sq(move)]
+                  + (*contHist[1])[movedPiece][to_sq(move)]
+                  + (*contHist[3])[movedPiece][to_sq(move)] < -3000 * depth + 3000)
                   continue;
 
               // Futility pruning: parent node (~5 Elo)
@@ -1093,6 +1094,14 @@ moves_loop: // When in check, search starts here
                   return beta;
           }
       }
+
+      // Capture extensions for PvNodes and cutNodes
+      else if (   (PvNode || cutNode) 
+               && captureOrPromotion 
+               && moveCount != 1)
+          extension = 1;
+
+      // Check extensions
       else if (   givesCheck
                && depth > 6
                && abs(ss->staticEval) > Value(100))
@@ -1173,8 +1182,8 @@ moves_loop: // When in check, search starts here
 
           // In general we want to cap the LMR depth search at newDepth. But if
           // reductions are really negative and movecount is low, we allow this move
-          // to be searched deeper than the first move, unless ttMove was extended by 2.
-          Depth d = std::clamp(newDepth - r, 1, newDepth + (r < -1 && moveCount <= 5 && !doubleExtension));
+          // to be searched deeper than the first move in specific cases.
+          Depth d = std::clamp(newDepth - r, 1, newDepth + (r < -1 && (moveCount <= 5 || (depth > 6 && PvNode)) && !doubleExtension));
 
           value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d, true);