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Capture Stat Tweak
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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 official-stockfish/Stockfish#1664

Bench: 5232010
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VoyagerOne authored and snicolet committed Jul 3, 2018
1 parent e7cfa5d commit 3279655
Showing 1 changed file with 5 additions and 3 deletions.
8 changes: 5 additions & 3 deletions src/search.cpp
Expand Up @@ -1155,8 +1155,8 @@ namespace {
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())
Expand Down Expand Up @@ -1448,7 +1448,9 @@ namespace {
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)
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