Since bestValue becomes value and beta - alpha is always non-negative,
extraReduction is always false, hence it has no effect.
This patch includes small changes to improve readability.
closes https://github.com/official-stockfish/Stockfish/pull/4505
No functional change
if (PvNode && value < beta) // Update alpha! Always alpha < beta
{
if (PvNode && value < beta) // Update alpha! Always alpha < beta
{
// Reduce other moves if we have found at least one score improvement (~1 Elo)
if ( depth > 1
// Reduce other moves if we have found at least one score improvement (~1 Elo)
if ( depth > 1
- && ((improving && complexity > 971) || (value < (5 * alpha + 75 * beta) / 87) || depth < 6)
+ && ( (improving && complexity > 971)
+ || value < (5 * alpha + 75 * beta) / 87
+ || depth < 6)
- && value > -12535) {
- bool extraReduction = depth > 2 && alpha > -12535 && bestValue != -VALUE_INFINITE && (value - bestValue) > (7 * (beta - alpha)) / 8;
- depth -= 1 + extraReduction;
- }
+ && value > -12535)
+ depth -= 1;
assert(depth > 0);
alpha = value;
assert(depth > 0);
alpha = value;