Depth reduction(bool i, Depth d, int mn, Value delta, Value rootDelta) {
int r = Reductions[d] * Reductions[mn];
- return (r + 1449 - int(delta) * 1001 / int(rootDelta)) / 1024 + (!i && r > 941);
+ return (r + 1449 - int(delta) * 937 / int(rootDelta)) / 1024 + (!i && r > 941);
}
constexpr int futility_move_count(bool improving, Depth depth) {
// History and stats update bonus, based on depth
int stat_bonus(Depth d) {
- return std::min(341 * d - 470, 1855);
+ return std::min(341 * d - 470, 1710);
}
// Add a small random component to draw evaluations to avoid 3-fold blindness
if (mainThread)
{
- int rootComplexity;
- Eval::evaluate(rootPos, &rootComplexity);
-
- mainThread->complexity = std::min(1.03 + (rootComplexity - 241) / 1552.0, 1.45);
+ if (!rootPos.checkers())
+ {
+ int rootComplexity;
+ Eval::evaluate(rootPos, &rootComplexity);
+ mainThread->complexity = std::min(1.03 + (rootComplexity - 241) / 1552.0, 1.45);
+ }
if (mainThread->bestPreviousScore == VALUE_INFINITE)
for (int i = 0; i < 4; ++i)
// Step 7. Razoring (~1 Elo).
// If eval is really low check with qsearch if it can exceed alpha, if it can't,
// return a fail low.
- if (eval < alpha - 426 - 252 * depth * depth)
+ if (eval < alpha - 426 - 256 * depth * depth)
{
value = qsearch<NonPV>(pos, ss, alpha - 1, alpha);
if (value < alpha)
&& (ss-1)->statScore < 18755
&& eval >= beta
&& eval >= ss->staticEval
- && ss->staticEval >= beta - 19 * depth - improvement / 13 + 253 + complexity / 25
+ && ss->staticEval >= beta - 20 * depth - improvement / 13 + 253 + complexity / 25
&& !excludedMove
&& pos.non_pawn_material(us)
&& (ss->ply >= thisThread->nmpMinPly || us != thisThread->nmpColor))
assert(eval - beta >= 0);
// Null move dynamic reduction based on depth, eval and complexity of position
- Depth R = std::min(int(eval - beta) / 168, 6) + depth / 3 + 4 - (complexity > 825);
+ Depth R = std::min(int(eval - beta) / 172, 6) + depth / 3 + 4 - (complexity > 825);
ss->currentMove = MOVE_NULL;
ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0];
if (PvNode && value < beta) // Update alpha! Always alpha < beta
{
- alpha = value;
// Reduce other moves if we have found at least one score improvement (~1 Elo)
if ( depth > 1
- && depth < 6
- && beta < 10534
- && alpha > -10534)
- depth -= 1;
+ && ((improving && complexity > 971) || (value < (5 * alpha + 75 * beta) / 87) || depth < 6)
+ && beta < 12535
+ && value > -12535) {
+ bool extraReduction = depth > 2 && alpha > -12535 && bestValue != -VALUE_INFINITE && (value - bestValue) > (7 * (beta - alpha)) / 8;
+ depth -= 1 + extraReduction;
+ }
assert(depth > 0);
+ alpha = value;
}
else
{