+ // Check if we have an upcoming move which draws by repetition, or
+ // if the opponent had an alternative move earlier to this position.
+ if ( pos.rule50_count() >= 3
+ && alpha < VALUE_DRAW
+ && !rootNode
+ && pos.has_game_cycle(ss->ply))
+ {
+ alpha = VALUE_DRAW;
+ if (alpha >= beta)
+ return alpha;
+ }
+
+ // Dive into quiescence search when the depth reaches zero
+ if (depth < ONE_PLY)
+ return qsearch<NT>(pos, ss, alpha, beta);
+