Tuning Search

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 359a774fd706cb4f7341b81c86e3675a85dad6c8..143d0883a4da699446ada1d049182c1b38b85de8 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -66,7 +66,7 @@ namespace {
 
   // Futility margin
   Value futility_margin(Depth d, bool improving) {
-    return Value(231 * (d - improving));
+    return Value(214 * (d - improving));
   }
 
   // Reductions lookup table, initialized at startup
@@ -74,7 +74,7 @@ namespace {
 
   Depth reduction(bool i, Depth d, int mn) {
     int r = Reductions[d] * Reductions[mn];
-    return (r + 503) / 1024 + (!i && r > 915);
+    return (r + 534) / 1024 + (!i && r > 904);
   }
 
   constexpr int futility_move_count(bool improving, Depth depth) {
@@ -83,7 +83,7 @@ namespace {
 
   // History and stats update bonus, based on depth
   int stat_bonus(Depth d) {
-    return d > 14 ? 66 : 6 * d * d + 231 * d - 206;
+    return d > 14 ? 73 : 6 * d * d + 229 * d - 215;
   }
 
   // Add a small random component to draw evaluations to avoid 3-fold blindness
@@ -377,7 +377,7 @@ void Thread::search() {
           // Start with a small aspiration window and, in the case of a fail
           // high/low, re-search with a bigger window until we don't fail
           // high/low anymore.
-          failedHighCnt = 0;
+          int failedHighCnt = 0;
           while (true)
           {
               Depth adjustedDepth = std::max(1, rootDepth - failedHighCnt - searchAgainCounter);
@@ -798,10 +798,10 @@ namespace {
     // Step 8. Null move search with verification search (~40 Elo)
     if (   !PvNode
         && (ss-1)->currentMove != MOVE_NULL
-        && (ss-1)->statScore < 24185
+        && (ss-1)->statScore < 23767
         &&  eval >= beta
         &&  eval >= ss->staticEval
-        &&  ss->staticEval >= beta - 22 * depth - 34 * improving + 162 * ss->ttPv + 159
+        &&  ss->staticEval >= beta - 20 * depth - 22 * improving + 168 * ss->ttPv + 159
         && !excludedMove
         &&  pos.non_pawn_material(us)
         && (ss->ply >= thisThread->nmpMinPly || us != thisThread->nmpColor))
@@ -809,7 +809,7 @@ namespace {
         assert(eval - beta >= 0);
 
         // Null move dynamic reduction based on depth and value
-        Depth R = (1062 + 68 * depth) / 256 + std::min(int(eval - beta) / 190, 3);
+        Depth R = (1090 + 81 * depth) / 256 + std::min(int(eval - beta) / 205, 3);
 
         ss->currentMove = MOVE_NULL;
         ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0];
@@ -922,7 +922,7 @@ moves_loop: // When in check, search starts from here
     ttCapture = ttMove && pos.capture_or_promotion(ttMove);
 
     // Step 11. A small Probcut idea, when we are in check
-    probCutBeta = beta + 400;
+    probCutBeta = beta + 409;
     if (   ss->inCheck
         && !PvNode
         && depth >= 4
@@ -1073,7 +1073,7 @@ moves_loop: // When in check, search starts from here
           {
               extension = 1;
               singularQuietLMR = !ttCapture;
-              if (!PvNode && value < singularBeta - 140)
+              if (!PvNode && value < singularBeta - 93)
                   extension = 2;
           }
 
@@ -1157,10 +1157,6 @@ moves_loop: // When in check, search starts from here
               if (ttCapture)
                   r++;
 
-              // Increase reduction at root if failing high
-              if (rootNode)
-                  r += thisThread->failedHighCnt * thisThread->failedHighCnt * moveCount / 512;
-
               // Increase reduction for cut nodes (~3 Elo)
               if (cutNode)
                   r += 2;
@@ -1169,11 +1165,11 @@ moves_loop: // When in check, search starts from here
                              + (*contHist[0])[movedPiece][to_sq(move)]
                              + (*contHist[1])[movedPiece][to_sq(move)]
                              + (*contHist[3])[movedPiece][to_sq(move)]
-                             - 4791;
+                             - 4923;
 
               // Decrease/increase reduction for moves with a good/bad history (~30 Elo)
               if (!ss->inCheck)
-                  r -= ss->statScore / 14790;
+                  r -= ss->statScore / 14721;
           }
 
           // In general we want to cap the LMR depth search at newDepth. But if