diff --git a/src/search.cpp b/src/search.cpp index 3f843641..e6ffcb19 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1388,7 +1388,9 @@ namespace { { assert(value_to_tt(nullValue, ply) == nullValue); - TT.store(posKey, nullValue, VALUE_TYPE_NS_LO, depth, MOVE_NONE); + // Special flag null values that are not zugzwang checked + ValueType vt = (depth < 6 * OnePly ? VALUE_TYPE_NS_LO : VALUE_TYPE_LOWER); + TT.store(posKey, nullValue, vt, depth, MOVE_NONE); return nullValue; } } else {