Introduce pawn structure based history

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 24f0d9946f7ec598604ba8b60eb937437523847f..0ffca247853faa03b1272d884b3560dc25edfc86 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -848,7 +848,8 @@ Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, boo
     {
         assert(probCutBeta < VALUE_INFINITE);
 
-        MovePicker mp(pos, ttMove, probCutBeta - ss->staticEval, &captureHistory);
+        MovePicker mp(pos, ttMove, probCutBeta - ss->staticEval, &captureHistory,
+                      thisThread->pawnHistory);
 
         while ((move = mp.next_move()) != MOVE_NONE)
             if (move != excludedMove && pos.legal(move))
@@ -904,7 +905,7 @@ moves_loop:  // When in check, search starts here
       prevSq != SQ_NONE ? thisThread->counterMoves[pos.piece_on(prevSq)][prevSq] : MOVE_NONE;
 
     MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, &captureHistory, contHist,
-                  countermove, ss->killers);
+                  thisThread->pawnHistory, countermove, ss->killers);
 
     value            = bestValue;
     moveCountPruning = singularQuietLMR = false;
@@ -988,7 +989,8 @@ moves_loop:  // When in check, search starts here
             {
                 int history = (*contHist[0])[movedPiece][to_sq(move)]
                             + (*contHist[1])[movedPiece][to_sq(move)]
-                            + (*contHist[3])[movedPiece][to_sq(move)];
+                            + (*contHist[3])[movedPiece][to_sq(move)]
+                            + thisThread->pawnHistory[pawn_structure(pos)][movedPiece][to_sq(move)];
 
                 // Continuation history based pruning (~2 Elo)
                 if (lmrDepth < 6 && history < -3498 * depth)
@@ -1463,7 +1465,7 @@ Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) {
     // will be generated.
     Square     prevSq = is_ok((ss - 1)->currentMove) ? to_sq((ss - 1)->currentMove) : SQ_NONE;
     MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, &thisThread->captureHistory,
-                  contHist, prevSq);
+                  contHist, thisThread->pawnHistory, prevSq);
 
     int quietCheckEvasions = 0;
 
@@ -1671,10 +1673,15 @@ void update_all_stats(const Position& pos,
 
         // Increase stats for the best move in case it was a quiet move
         update_quiet_stats(pos, ss, bestMove, bestMoveBonus);
+        thisThread->pawnHistory[pawn_structure(pos)][moved_piece][to_sq(bestMove)]
+          << quietMoveBonus;
 
         // Decrease stats for all non-best quiet moves
         for (int i = 0; i < quietCount; ++i)
         {
+            thisThread->pawnHistory[pawn_structure(pos)][pos.moved_piece(quietsSearched[i])]
+                                   [to_sq(quietsSearched[i])]
+              << -bestMoveBonus;
             thisThread->mainHistory[us][from_to(quietsSearched[i])] << -bestMoveBonus;
             update_continuation_histories(ss, pos.moved_piece(quietsSearched[i]),
                                           to_sq(quietsSearched[i]), -bestMoveBonus);