Simplify cutnode depth condition

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 76d0545ac50bd7f619f88db3785ee6c0f3e4c316..a745d3bfdd0ed16933a9d53dcd8f7ab830637940 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -80,8 +80,9 @@ namespace {
   int Reductions[MAX_MOVES]; // [depth or moveNumber]
 
   Depth reduction(bool i, Depth d, int mn, Value delta, Value rootDelta) {
-    int r = Reductions[d] * Reductions[mn];
-    return (r + 1372 - int(delta) * 1073 / int(rootDelta)) / 1024 + (!i && r > 936);
+    int reductionScale = Reductions[d] * Reductions[mn];
+    return  (reductionScale + 1372 - int(delta) * 1073 / int(rootDelta)) / 1024
+          + (!i && reductionScale > 936);
   }
 
   constexpr int futility_move_count(bool improving, Depth depth) {
@@ -1130,7 +1131,7 @@ moves_loop: // When in check, search starts here
       // Decrease further on cutNodes. (~1 Elo)
       if (   ss->ttPv
           && !likelyFailLow)
-          r -= cutNode && tte->depth() >= depth + 3 ? 3 : 2;
+          r -= cutNode && tte->depth() >= depth ? 3 : 2;
 
       // Decrease reduction if opponent's move count is high (~1 Elo)
       if ((ss-1)->moveCount > 8)