if (rootDepth >= 5 * ONE_PLY)
{
Value previousScore = rootMoves[pvIdx].previousScore;
- delta = Value(18);
+ delta = Value(20);
alpha = std::max(previousScore - delta,-VALUE_INFINITE);
beta = std::min(previousScore + delta, VALUE_INFINITE);
// Start with a small aspiration window and, in the case of a fail
// high/low, re-search with a bigger window until we don't fail
// high/low anymore.
+ int failedHighCnt = 0;
while (true)
{
- bestValue = ::search<PV>(rootPos, ss, alpha, beta, rootDepth, false);
+ Depth adjustedDepth = std::max(ONE_PLY, rootDepth - failedHighCnt * ONE_PLY);
+ bestValue = ::search<PV>(rootPos, ss, alpha, beta, adjustedDepth, false);
// Bring the best move to the front. It is critical that sorting
// is done with a stable algorithm because all the values but the
if (mainThread)
{
+ failedHighCnt = 0;
failedLow = true;
Threads.stopOnPonderhit = false;
}
}
else if (bestValue >= beta)
+ {
beta = std::min(bestValue + delta, VALUE_INFINITE);
+ if (mainThread)
+ ++failedHighCnt;
+ }
else
break;