alpha = std::max(rootMoves[PVIdx].previousScore - delta,-VALUE_INFINITE);
beta = std::min(rootMoves[PVIdx].previousScore + delta, VALUE_INFINITE);
- // Adjust contempt based on current bestValue
- ct = Options["Contempt"] * PawnValueEg / 100 // From centipawns
- + (bestValue > 500 ? 50: // Dynamic contempt
- bestValue < -500 ? -50:
- bestValue / 10);
+ ct = Options["Contempt"] * PawnValueEg / 100; // From centipawns
+
+ // Adjust contempt based on current bestValue (dynamic contempt)
+ int sign = (bestValue > 0) - (bestValue < 0);
+ ct += bestValue > 500 ? 70 :
+ bestValue < -500 ? -70 :
+ bestValue / 10 + sign * int(std::round(3.22 * log(1 + abs(bestValue))));
Eval::Contempt = (us == WHITE ? make_score(ct, ct / 2)
: -make_score(ct, ct / 2));
goto moves_loop;
// Step 7. Razoring (skipped when in check)
- if ( !PvNode
- && depth <= ONE_PLY)
+ if ( !PvNode
+ && depth <= 2 * ONE_PLY)
{
- if (eval + RazorMargin1 <= alpha)
+ if ( depth == ONE_PLY
+ && eval + RazorMargin1 <= alpha)
return qsearch<NonPV, false>(pos, ss, alpha, alpha+1);
- }
- else if ( !PvNode
- && depth <= 2 * ONE_PLY
- && eval + RazorMargin2 <= alpha)
- {
- Value ralpha = alpha - RazorMargin2;
- Value v = qsearch<NonPV, false>(pos, ss, ralpha, ralpha+1);
- if (v <= ralpha)
- return v;
+
+ else if (eval + RazorMargin2 <= alpha)
+ {
+ Value ralpha = alpha - RazorMargin2;
+ Value v = qsearch<NonPV, false>(pos, ss, ralpha, ralpha+1);
+
+ if (v <= ralpha)
+ return v;
+ }
}
// Step 8. Futility pruning: child node (skipped when in check)
Value rbeta = std::min(beta + 200, VALUE_INFINITE);
MovePicker mp(pos, ttMove, rbeta - ss->staticEval, &thisThread->captureHistory);
int probCutCount = 0;
+
while ( (move = mp.next_move()) != MOVE_NONE
&& probCutCount < depth / ONE_PLY - 3)
if (pos.legal(move))
value = -search<NonPV>(pos, ss+1, -rbeta, -rbeta+1, depth - 4 * ONE_PLY, !cutNode, false);
pos.undo_move(move);
+
if (value >= rbeta)
return value;
}