bool captureOrPromotion, doFullDepthSearch, moveCountPruning,
ttCapture, singularQuietLMR, noLMRExtension;
Piece movedPiece;
- int moveCount, captureCount, quietCount;
+ int moveCount, captureCount, quietCount, bestMoveCount;
// Step 1. Initialize node
ss->inCheck = pos.checkers();
priorCapture = pos.captured_piece();
Color us = pos.side_to_move();
- moveCount = captureCount = quietCount = ss->moveCount = 0;
+ moveCount = bestMoveCount = captureCount = quietCount = ss->moveCount = 0;
bestValue = -VALUE_INFINITE;
maxValue = VALUE_INFINITE;
{
Depth r = reduction(improving, depth, moveCount, rangeReduction > 2);
- // Decrease reduction if on the PV (~1 Elo)
- if (PvNode)
+ // Decrease reduction if on the PV (~2 Elo)
+ if ( PvNode
+ && bestMoveCount <= 3)
r--;
// Decrease reduction if the ttHit running average is large (~0 Elo)
update_pv(ss->pv, move, (ss+1)->pv);
if (PvNode && value < beta) // Update alpha! Always alpha < beta
+ {
alpha = value;
+ bestMoveCount++;
+ }
else
{
assert(value >= beta); // Fail high