diff --git a/src/tt.cpp b/src/tt.cpp index b7d47e74..f3af6432 100644 --- a/src/tt.cpp +++ b/src/tt.cpp @@ -197,9 +197,11 @@ void TranspositionTable::extract_pv(const Position& pos, Move bestMove, Move pv[ pv[ply] = bestMove; p.do_move(pv[ply++], st); - // Try to add moves from TT while possible + // Extract moves from TT when possible. We try hard to always + // get a ponder move, that's the reason of ply < 2 conditions. while ( (tte = retrieve(p.get_key())) != NULL && tte->move() != MOVE_NONE + && (tte->type() == VALUE_TYPE_EXACT || ply < 2) && move_is_legal(p, tte->move()) && (!p.is_draw() || ply < 2) && ply < PLY_MAX)