LMR Capture Tweak

Increase capture reduction by comparing opponent's stat score STC: (Yellow) LLR: -2.96 (-2.94,2.94) [0.00,5.00] Total: 92291 W: 18647 L: 18350 D: 55294 http://tests.stockfishchess.org/tests/view/5b04225e0ebc5914abc1291b LTC: LLR: 2.95 (-2.94,2.94) [0.00,5.00] Total: 20176 W: 3061 L: 2868 D: 14247 http://tests.stockfishchess.org/tests/view/5b04bb3f0ebc5914abc129a3 How to continue? • we could try a different value for the capture history threeshold Closes #1612 Bench: 5167159
official-stockfish · May 24, 2018 · 3d6995e · 3d6995e · gcp · May 30, 2018
1 parent d5d23bf
commit 3d6995e
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/src/search.cpp b/src/search.cpp
@@ -995,7 +995,14 @@ namespace {
           Depth r = reduction<PvNode>(improving, depth, moveCount);
 
           if (captureOrPromotion) // (~5 Elo)
+          {
+              //Increase reduction by comparing opponent's stat score
+              if (   (ss-1)->statScore >= 0 
+                  && thisThread->captureHistory[movedPiece][to_sq(move)][type_of(pos.captured_piece())] < 0)
+                  r += ONE_PLY;
+
               r -= r ? ONE_PLY : DEPTH_ZERO;
+          }
           else
           {
               // Decrease reduction if opponent's move count is high (~5 Elo)