Remove depth dependence and use same limit (2000) as stat_bonus

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 92ec9eca77dae75a800adf0f719c753288a233a4..c4ed73372df2040ffee3bc7093e61e9301011ecd 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -801,7 +801,7 @@ namespace {
     // Use static evaluation difference to improve quiet move ordering
     if (is_ok((ss-1)->currentMove) && !(ss-1)->inCheck && !priorCapture)
     {
-        int bonus = std::clamp(-depth * 4 * int((ss-1)->staticEval + ss->staticEval), -1000, 1000);
+        int bonus = std::clamp(-16 * int((ss-1)->staticEval + ss->staticEval), -2000, 2000);
         thisThread->mainHistory[~us][from_to((ss-1)->currentMove)] << bonus;
     }
 
@@ -1054,17 +1054,21 @@ moves_loop: // When in check, search starts here
           }
           else
           {
+              int history =   (*contHist[0])[movedPiece][to_sq(move)]
+                            + (*contHist[1])[movedPiece][to_sq(move)]
+                            + (*contHist[3])[movedPiece][to_sq(move)];
+
               // Continuation history based pruning (~20 Elo)
-              if (lmrDepth < 5
-                  && (*contHist[0])[movedPiece][to_sq(move)]
-                  + (*contHist[1])[movedPiece][to_sq(move)]
-                  + (*contHist[3])[movedPiece][to_sq(move)] < -3000 * depth + 3000)
+              if (   lmrDepth < 5
+                  && history < -3000 * depth + 3000)
                   continue;
 
+              history += thisThread->mainHistory[us][from_to(move)];
+
               // Futility pruning: parent node (~5 Elo)
               if (   !ss->inCheck
                   && lmrDepth < 8
-                  && ss->staticEval + 172 + 145 * lmrDepth <= alpha)
+                  && ss->staticEval + 142 + 139 * lmrDepth + history / 64 <= alpha)
                   continue;
 
               // Prune moves with negative SEE (~20 Elo)