if (!RootNode)
{
// Step 2. Check for aborted search and immediate draw
- if (Signals.stop || pos.is_draw<false>() || ss->ply > MAX_PLY)
+ if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY)
return DrawValue[pos.side_to_move()];
// Step 3. Mate distance pruning. Even if we mate at the next move our score
// Never assume anything on values stored in TT
if ( (ss->staticEval = eval = tte->eval_value()) == VALUE_NONE
||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE)
- eval = ss->staticEval = evaluate(pos, ss->evalMargin);
+ eval = ss->staticEval = evaluate(pos, ss->evalMargin, &ss->ei);
// Can ttValue be used as a better position evaluation?
if (ttValue != VALUE_NONE)
}
else
{
- eval = ss->staticEval = evaluate(pos, ss->evalMargin);
+ eval = ss->staticEval = evaluate(pos, ss->evalMargin, &ss->ei);
TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE,
ss->staticEval, ss->evalMargin);
}
&& !ss->skipNullMove
&& depth < 4 * ONE_PLY
&& !inCheck
- && eval - FutilityMargins[depth][0] >= beta
+ && eval - futility_margin(depth, (ss-1)->futilityMoveCount) >= beta
&& abs(beta) < VALUE_MATE_IN_MAX_PLY
&& pos.non_pawn_material(pos.side_to_move()))
- return eval - FutilityMargins[depth][0];
+ return eval - futility_margin(depth, (ss-1)->futilityMoveCount);
// Step 8. Null move search with verification search (is omitted in PV nodes)
if ( !PvNode
if (nullValue >= VALUE_MATE_IN_MAX_PLY)
nullValue = beta;
- if (depth < 6 * ONE_PLY)
+ if (depth < 12 * ONE_PLY)
return nullValue;
// Do verification search at high depths
<< " currmovenumber " << moveCount + PVIdx << sync_endl;
}
+ ss->futilityMoveCount = 0;
ext = DEPTH_ZERO;
captureOrPromotion = pos.is_capture_or_promotion(move);
givesCheck = pos.move_gives_check(move, ci);
&& !captureOrPromotion
&& !inCheck
&& !dangerous
- && move != ttMove
+ /* && move != ttMove Already implicit in the next condition */
&& bestValue > VALUE_MATED_IN_MAX_PLY)
{
// Move count based pruning
// but fixing this made program slightly weaker.
Depth predictedDepth = newDepth - reduction<PvNode>(depth, moveCount);
futilityValue = ss->staticEval + ss->evalMargin + futility_margin(predictedDepth, moveCount)
- + 2 * Gain[pos.piece_moved(move)][to_sq(move)];
+ + Gain[pos.piece_moved(move)][to_sq(move)];
if (futilityValue < beta)
{
continue;
}
+
+ // We have not pruned the move that will be searched, but remember how
+ // far in the move list we are to be more aggressive in the child node.
+ ss->futilityMoveCount = moveCount;
}
// Check for legality only before to do the move
ss->ply = (ss-1)->ply + 1;
// Check for an instant draw or maximum ply reached
- if (pos.is_draw<true>() || ss->ply > MAX_PLY)
+ if (pos.is_draw() || ss->ply > MAX_PLY)
return DrawValue[pos.side_to_move()];
// Decide whether or not to include checks, this fixes also the type of
// Never assume anything on values stored in TT
if ( (ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE
||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE)
- ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
+ ss->staticEval = bestValue = evaluate(pos, ss->evalMargin, &ss->ei);
}
else
- ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
+ ss->staticEval = bestValue = evaluate(pos, ss->evalMargin, &ss->ei);
// Stand pat. Return immediately if static value is at least beta
if (bestValue >= beta)
continue;
}
- // Prune moves with negative or equal SEE
+ // Prune moves with negative or equal SEE and also moves with positive
+ // SEE where capturing piece loses a tempo and SEE < beta - futilityBase.
if ( futilityBase < beta
&& depth < DEPTH_ZERO
- && pos.see(move) <= 0)
+ && pos.see(move, beta - futilityBase) <= 0)
{
bestValue = std::max(bestValue, futilityBase);
continue;
&& pos.is_pseudo_legal(m = tte->move()) // Local copy, TT could change
&& pos.pl_move_is_legal(m, pos.pinned_pieces())
&& ply < MAX_PLY
- && (!pos.is_draw<false>() || ply < 2));
+ && (!pos.is_draw() || ply < 2));
pv.push_back(MOVE_NONE); // Must be zero-terminating