// Minimum depth for use of singular extension
const Depth SingularExtensionDepth[2] = { 8 * ONE_PLY /* non-PV */, 6 * ONE_PLY /* PV */};
- // If the TT move is at least SingularExtensionMargin better than the
- // remaining ones we will extend it.
- const Value SingularExtensionMargin = Value(0x20);
-
// Step 12. Futility pruning
// Futility margin for quiescence search
if (abs(ttValue) < VALUE_KNOWN_WIN)
{
- Value b = ttValue - SingularExtensionMargin;
+ Value b = ttValue - depth;
ss->excludedMove = move;
ss->skipNullMove = true;
Value v = search<NonPV>(pos, ss, b - 1, b, depth / 2, ply);