HistoryStats History;
CounterMovesHistoryStats CounterMovesHistory;
GainsStats Gains;
- MovesStats Countermoves, Followupmoves;
+ MovesStats Countermoves;
template <NodeType NT, bool SpNode>
Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode);
CounterMovesHistory.clear();
Gains.clear();
Countermoves.clear();
- Followupmoves.clear();
size_t multiPV = Options["MultiPV"];
Skill skill(Options["Skill Level"]);
{
ss->currentMove = ttMove; // Can be MOVE_NONE
- // If ttMove is quiet, update killers, history, counter move and followup move on TT hit
+ // If ttMove is quiet, update killers, history, counter move on TT hit
if (ttValue >= beta && ttMove && !pos.capture_or_promotion(ttMove) && !inCheck)
update_stats(pos, ss, ttMove, depth, nullptr, 0);
Move countermoves[] = { Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].first,
Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].second };
- Square prevOwnMoveSq = to_sq((ss-2)->currentMove);
- Move followupmoves[] = { Followupmoves[pos.piece_on(prevOwnMoveSq)][prevOwnMoveSq].first,
- Followupmoves[pos.piece_on(prevOwnMoveSq)][prevOwnMoveSq].second };
-
- MovePicker mp(pos, ttMove, depth, History, CounterMovesHistory, countermoves, followupmoves, ss);
+ MovePicker mp(pos, ttMove, depth, History, CounterMovesHistory, countermoves, ss);
CheckInfo ci(pos);
value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
improving = ss->staticEval >= (ss-2)->staticEval
if ( (!PvNode && cutNode)
|| History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO
- || CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq][pos.piece_on(to_sq(move))][to_sq(move)]
- + History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO)
+ || ( History[pos.piece_on(to_sq(move))][to_sq(move)]
+ + CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq]
+ [pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO))
ss->reduction += ONE_PLY;
if (move == countermoves[0] || move == countermoves[1])
bestValue = excludedMove ? alpha
: inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()];
- // Quiet best move: update killers, history, countermoves and followupmoves
+ // Quiet best move: update killers, history and countermoves
else if (bestValue >= beta && !pos.capture_or_promotion(bestMove) && !inCheck)
update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount - 1);
*pv = MOVE_NONE;
}
- // update_stats() updates killers, history, countermoves and followupmoves
- // stats after a fail-high of a quiet move.
+ // update_stats() updates killers, history and countermoves stats after a fail-high
+ // of a quiet move.
void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) {
cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
}
+ // Extra penalty for TT move in previous ply when it gets refuted
if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove)
{
Square prevPrevSq = to_sq((ss-2)->currentMove);
- Followupmoves.update(pos.piece_on(prevPrevSq), prevPrevSq, move);
-
- // Extra penalty for TT move in previous ply when it gets refuted
HistoryStats& ttMoveCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
ttMoveCmh.update(pos.piece_on(prevSq), prevSq, -bonus - 2 * depth / ONE_PLY - 1);
}