X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=d34e182392843b4874a07b1b5858610a4e78a143;hp=01de12a4cea99b662ce0134349be1b3c3dadaeb5;hb=abd4400c874ab178d04c08d3668f3843aece114e;hpb=3a3ca6af0390d74427c218f29cb5fe1a913efb42 diff --git a/src/search.cpp b/src/search.cpp index 01de12a4..d34e1823 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -86,9 +86,8 @@ namespace { } // Add a small random component to draw evaluations to avoid 3fold-blindness - Value value_draw(Depth depth, Thread* thisThread) { - return depth < 4 * ONE_PLY ? VALUE_DRAW - : VALUE_DRAW + Value(2 * (thisThread->nodes & 1) - 1); + Value value_draw(Thread* thisThread) { + return VALUE_DRAW + Value(2 * (thisThread->nodes & 1) - 1); } // Skill structure is used to implement strength limit @@ -574,7 +573,7 @@ namespace { && !rootNode && pos.has_game_cycle(ss->ply)) { - alpha = value_draw(depth, pos.this_thread()); + alpha = value_draw(pos.this_thread()); if (alpha >= beta) return alpha; } @@ -624,7 +623,7 @@ namespace { || pos.is_draw(ss->ply) || ss->ply >= MAX_PLY) return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos) - : value_draw(depth, pos.this_thread()); + : value_draw(pos.this_thread()); // Step 3. Mate distance pruning. Even if we mate at the next move our score // would be at best mate_in(ss->ply+1), but if alpha is already bigger because @@ -763,7 +762,7 @@ namespace { ss->staticEval = eval = evaluate(pos); if (eval == VALUE_DRAW) - eval = value_draw(depth, thisThread); + eval = value_draw(thisThread); // Can ttValue be used as a better position evaluation? if ( ttValue != VALUE_NONE @@ -1009,7 +1008,7 @@ moves_loop: // When in check, search starts from here && pos.advanced_pawn_push(move) && pos.pawn_passed(us, to_sq(move))) extension = ONE_PLY; - + // Castling extension if (type_of(move) == CASTLING) extension = ONE_PLY;