std::string msg1 =
"Network evaluation parameters compatible with the engine must be available.";
std::string msg2 = "The network file " + eval_file + " was not loaded successfully.";
- std::string msg3 =
- "The UCI option EvalFile might need to specify the full path, including the directory name, to the network file.";
- std::string msg4 =
- "The default net can be downloaded from: https://tests.stockfishchess.org/api/nn/"
- + std::string(EvalFileDefaultName);
+ std::string msg3 = "The UCI option EvalFile might need to specify the full path, "
+ "including the directory name, to the network file.";
+ std::string msg4 = "The default net can be downloaded from: "
+ "https://tests.stockfishchess.org/api/nn/"
+ + std::string(EvalFileDefaultName);
std::string msg5 = "The engine will be terminated now.";
sync_cout << "info string ERROR: " << msg1 << sync_endl;
// NOTE: The parameter states_to_update is an array of position states, ending with nullptr.
// All states must be sequential, that is states_to_update[i] must either be reachable
- // by repeatedly applying ->previous from states_to_update[i+1] or states_to_update[i] == nullptr.
- // computed_st must be reachable by repeatedly applying ->previous on states_to_update[0], if not nullptr.
+ // by repeatedly applying ->previous from states_to_update[i+1] or
+ // states_to_update[i] == nullptr.
+ // computed_st must be reachable by repeatedly applying ->previous on
+ // states_to_update[0], if not nullptr.
template<Color Perspective, size_t N>
void update_accumulator_incremental(const Position& pos,
StateInfo* computed_st,
int failedHighCnt = 0;
while (true)
{
- // Adjust the effective depth searched, but ensure at least one effective increment for every
- // four searchAgain steps (see issue #2717).
+ // Adjust the effective depth searched, but ensure at least one effective increment
+ // for every four searchAgain steps (see issue #2717).
Depth adjustedDepth =
std::max(1, rootDepth - failedHighCnt - 3 * (searchAgainCounter + 1) / 4);
bestValue = Stockfish::search<Root>(rootPos, ss, alpha, beta, adjustedDepth, false);
if (!ttCapture)
update_quiet_stats(pos, ss, ttMove, stat_bonus(depth));
- // Extra penalty for early quiet moves of the previous ply (~0 Elo on STC, ~2 Elo on LTC)
+ // Extra penalty for early quiet moves of
+ // the previous ply (~0 Elo on STC, ~2 Elo on LTC).
if (prevSq != SQ_NONE && (ss - 1)->moveCount <= 2 && !priorCapture)
update_continuation_histories(ss - 1, pos.piece_on(prevSq), prevSq,
-stat_bonus(depth + 1));
}
else if (excludedMove)
{
- // Providing the hint that this node's accumulator will be used often brings significant Elo gain (~13 Elo)
+ // Providing the hint that this node's accumulator will be used often
+ // brings significant Elo gain (~13 Elo).
Eval::NNUE::hint_common_parent_position(pos);
eval = ss->staticEval;
}
}
}
- // Step 10. If the position doesn't have a ttMove, decrease depth by 2
- // (or by 4 if the TT entry for the current position was hit and the stored depth is greater than or equal to the current depth).
+ // Step 10. If the position doesn't have a ttMove, decrease depth by 2,
+ // or by 4 if the TT entry for the current position was hit and
+ // the stored depth is greater than or equal to the current depth.
// Use qsearch if depth is equal or below zero (~9 Elo)
if (PvNode && !ttMove)
depth -= 2 + 2 * (ss->ttHit && tte->depth() >= depth);
if (capture || givesCheck)
{
// Futility pruning for captures (~2 Elo)
- if (!givesCheck && lmrDepth < 7 && !ss->inCheck
- && ss->staticEval + 188 + 206 * lmrDepth + PieceValue[pos.piece_on(to_sq(move))]
- + captureHistory[movedPiece][to_sq(move)]
- [type_of(pos.piece_on(to_sq(move)))]
- / 7
- < alpha)
- continue;
+ if (!givesCheck && lmrDepth < 7 && !ss->inCheck)
+ {
+ Piece capturedPiece = pos.piece_on(to_sq(move));
+ int futilityEval =
+ ss->staticEval + 188 + 206 * lmrDepth + PieceValue[capturedPiece]
+ + captureHistory[movedPiece][to_sq(move)][type_of(capturedPiece)] / 7;
+ if (futilityEval < alpha)
+ continue;
+ }
// SEE based pruning for captures and checks (~11 Elo)
if (!pos.see_ge(move, Value(-185) * depth))
// that depth margin and singularBeta margin are known for having non-linear
// scaling. Their values are optimized to time controls of 180+1.8 and longer
// so changing them requires tests at this type of time controls.
- if (!rootNode
+ // Recursive singular search is avoided.
+ if (!rootNode && move == ttMove && !excludedMove
&& depth >= 4 - (thisThread->completedDepth > 24) + 2 * (PvNode && tte->is_pv())
- && move == ttMove && !excludedMove // Avoid recursive singular search
&& abs(ttValue) < VALUE_TB_WIN_IN_MAX_PLY && (tte->bound() & BOUND_LOWER)
&& tte->depth() >= depth - 3)
{
else if (singularBeta >= beta)
return singularBeta;
- // If the eval of ttMove is greater than beta, we reduce it (negative extension) (~7 Elo)
+ // If the eval of ttMove is greater than beta, reduce it (negative extension) (~7 Elo)
else if (ttValue >= beta)
extension = -2 - !PvNode;
else if (cutNode)
extension = depth < 19 ? -2 : -1;
- // If the eval of ttMove is less than value, we reduce it (negative extension) (~1 Elo)
+ // If the eval of ttMove is less than value, reduce it (negative extension) (~1 Elo)
else if (ttValue <= value)
extension = -1;
}