SearchStack ss[PLY_MAX_PLUS_2];
Value bestValues[PLY_MAX_PLUS_2];
int bestMoveChanges[PLY_MAX_PLUS_2];
- int depth, researchCountFL, researchCountFH, aspirationDelta;
+ int depth, aspirationDelta;
Value value, alpha, beta;
Move bestMove, easyMove;
// Iterative deepening loop
while (++depth <= PLY_MAX && (!MaxDepth || depth <= MaxDepth) && !StopRequest)
{
- Rml.bestMoveChanges = researchCountFL = researchCountFH = 0;
+ Rml.bestMoveChanges = 0;
cout << "info depth " << depth << endl;
// Calculate dynamic aspiration window based on previous iterations
// Start with a small aspiration window and, in case of fail high/low,
// research with bigger window until not failing high/low anymore.
- while (true)
- {
+ do {
// Search starting from ss+1 to allow calling update_gains()
value = search<PV, false, true>(pos, ss+1, alpha, beta, depth * ONE_PLY, 0);
// otherwise exit the fail high/low loop.
if (value >= beta)
{
- beta = Min(beta + aspirationDelta * (1 << researchCountFH), VALUE_INFINITE);
- researchCountFH++;
+ beta = Min(beta + aspirationDelta, VALUE_INFINITE);
+ aspirationDelta += aspirationDelta / 2;
}
else if (value <= alpha)
{
AspirationFailLow = true;
StopOnPonderhit = false;
- alpha = Max(alpha - aspirationDelta * (1 << researchCountFL), -VALUE_INFINITE);
- researchCountFL++;
+ alpha = Max(alpha - aspirationDelta, -VALUE_INFINITE);
+ aspirationDelta += aspirationDelta / 2;
}
else
break;
- }
+
+ } while (abs(value) < VALUE_KNOWN_WIN);
// Collect info about search result
bestMove = Rml[0].pv[0];