The values used in this patch are taken from a SPSA parameter tuning session
originated by Unai Corzo (@unaiic), but the final difference of his tune was
multiplied x2 by hand. Most of the credits should go to him :-)
STC:
https://tests.stockfishchess.org/tests/view/
602f03d07f517a561bc49d40
LLR: 2.94 (-2.94,2.94) {-0.25,1.25}
Total: 67664 W: 6252 L: 6035 D: 55377
Ptnml(0-2): 256, 4799, 23527, 4972, 278
LTC:
https://tests.stockfishchess.org/tests/view/
602f41697f517a561bc49d5a
LLR: 2.96 (-2.94,2.94) {0.25,1.25}
Total: 26256 W: 1034 L: 906 D: 24316
Ptnml(0-2): 10, 804, 11377, 922, 15
Closes https://github.com/official-stockfish/Stockfish/pull/3363
Bench:
3957653
// Step 8. Null move search with verification search (~40 Elo)
if ( !PvNode
&& (ss-1)->currentMove != MOVE_NULL
// Step 8. Null move search with verification search (~40 Elo)
if ( !PvNode
&& (ss-1)->currentMove != MOVE_NULL
- && (ss-1)->statScore < 22661
+ && (ss-1)->statScore < 24185
&& eval >= beta
&& eval >= ss->staticEval
&& ss->staticEval >= beta - 24 * depth - 34 * improving + 162 * ss->ttPv + 159
&& eval >= beta
&& eval >= ss->staticEval
&& ss->staticEval >= beta - 24 * depth - 34 * improving + 162 * ss->ttPv + 159
&& (*contHist[0])[movedPiece][to_sq(move)]
+ (*contHist[1])[movedPiece][to_sq(move)]
+ (*contHist[3])[movedPiece][to_sq(move)]
&& (*contHist[0])[movedPiece][to_sq(move)]
+ (*contHist[1])[movedPiece][to_sq(move)]
+ (*contHist[3])[movedPiece][to_sq(move)]
- + (*contHist[5])[movedPiece][to_sq(move)] / 3 < 26237)
+ + (*contHist[5])[movedPiece][to_sq(move)] / 3 < 28255)
continue;
// Prune moves with negative SEE (~20 Elo)
continue;
// Prune moves with negative SEE (~20 Elo)
|| moveCountPruning
|| ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha
|| cutNode
|| moveCountPruning
|| ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha
|| cutNode
- || (!PvNode && !formerPv && captureHistory[movedPiece][to_sq(move)][type_of(pos.captured_piece())] < 4506)
+ || (!PvNode && !formerPv && captureHistory[movedPiece][to_sq(move)][type_of(pos.captured_piece())] < 3678)
|| thisThread->ttHitAverage < 432 * TtHitAverageResolution * TtHitAverageWindow / 1024))
{
Depth r = reduction(improving, depth, moveCount);
|| thisThread->ttHitAverage < 432 * TtHitAverageResolution * TtHitAverageWindow / 1024))
{
Depth r = reduction(improving, depth, moveCount);
+ (*contHist[0])[movedPiece][to_sq(move)]
+ (*contHist[1])[movedPiece][to_sq(move)]
+ (*contHist[3])[movedPiece][to_sq(move)]
+ (*contHist[0])[movedPiece][to_sq(move)]
+ (*contHist[1])[movedPiece][to_sq(move)]
+ (*contHist[3])[movedPiece][to_sq(move)]
// Decrease/increase reduction by comparing opponent's stat score (~10 Elo)
if (ss->statScore >= -89 && (ss-1)->statScore < -116)
// Decrease/increase reduction by comparing opponent's stat score (~10 Elo)
if (ss->statScore >= -89 && (ss-1)->statScore < -116)
// use sum of main history and first continuation history with an offset
if (ss->inCheck)
r -= (thisThread->mainHistory[us][from_to(move)]
// use sum of main history and first continuation history with an offset
if (ss->inCheck)
r -= (thisThread->mainHistory[us][from_to(move)]
- + (*contHist[0])[movedPiece][to_sq(move)] - 4341) / 16384;
+ + (*contHist[0])[movedPiece][to_sq(move)] - 3833) / 16384;
- r -= ss->statScore / 14382;
+ r -= ss->statScore / 14790;
}
Depth d = std::clamp(newDepth - r, 1, newDepth);
}
Depth d = std::clamp(newDepth - r, 1, newDepth);