Capture Stat Tweak

Penalize capture moves that fail to create a cutoff even at quiet move cutoff.

STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 19004 W: 4284 L: 4059 D: 10661
http://tests.stockfishchess.org/tests/view/5b3a7d4d0ebc5902b9ffb6ea

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 23100 W: 3981 L: 3765 D: 15354
http://tests.stockfishchess.org/tests/view/5b3aa4550ebc5902b9ffb8cf

Closes https://github.com/official-stockfish/Stockfish/pull/1664

Bench: 5232010

diff --git a/src/search.cpp b/src/search.cpp
index 3f89c0400c24d2f54e9aee6fc52eac7a5f5cd56c..97ad9912b6b38e21c890e462f30cca55efbacba5 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1155,8 +1155,8 @@ moves_loop: // When in check, search starts from here
         if (!pos.capture_or_promotion(bestMove))
             update_quiet_stats(pos, ss, bestMove, quietsSearched, quietCount,
                                stat_bonus(depth + (bestValue > beta + PawnValueMg ? ONE_PLY : DEPTH_ZERO)));
         if (!pos.capture_or_promotion(bestMove))
             update_quiet_stats(pos, ss, bestMove, quietsSearched, quietCount,
                                stat_bonus(depth + (bestValue > beta + PawnValueMg ? ONE_PLY : DEPTH_ZERO)));

-        else
-            update_capture_stats(pos, bestMove, capturesSearched, captureCount, stat_bonus(depth + ONE_PLY));
+
+        update_capture_stats(pos, bestMove, capturesSearched, captureCount, stat_bonus(depth + ONE_PLY));

 
         // Extra penalty for a quiet TT move in previous ply when it gets refuted
         if ((ss-1)->moveCount == 1 && !pos.captured_piece())
 
         // Extra penalty for a quiet TT move in previous ply when it gets refuted
         if ((ss-1)->moveCount == 1 && !pos.captured_piece())


@@ -1448,7 +1448,9 @@ moves_loop: // When in check, search starts from here
       CapturePieceToHistory& captureHistory =  pos.this_thread()->captureHistory;
       Piece moved_piece = pos.moved_piece(move);
       PieceType captured = type_of(pos.piece_on(to_sq(move)));
       CapturePieceToHistory& captureHistory =  pos.this_thread()->captureHistory;
       Piece moved_piece = pos.moved_piece(move);
       PieceType captured = type_of(pos.piece_on(to_sq(move)));

-      captureHistory[moved_piece][to_sq(move)][captured] << bonus;
+
+      if (pos.capture_or_promotion(move))
+          captureHistory[moved_piece][to_sq(move)][captured] << bonus;

 
       // Decrease all the other played capture moves
       for (int i = 0; i < captureCnt; ++i)
 
       // Decrease all the other played capture moves
       for (int i = 0; i < captureCnt; ++i)