-/// The Stats struct stores moves statistics. According to the template parameter
-/// the class can store History, Gains and Refutations statistics. History records
-/// how often different moves have been successful or unsuccessful during the
-/// current search and is used for reduction and move ordering decisions. Gains
-/// records the move's best evaluation gain from one ply to the next and is used
-/// for pruning decisions. Refutations store the move that refute a previous one.
-/// Entries are stored according only to moving piece and destination square, in
-/// particular two moves with different origin but same destination and same piece
-/// will be considered identical.
-template<bool Gain, typename T>
-struct Stats {
+ void fill(const T& v) {
+ T* p = &(*this)[0][0];
+ std::fill(p, p + sizeof(*this) / sizeof(*p), v);
+ }
+
+ void update(T& entry, int bonus, const int D) {
+
+ assert(abs(bonus) <= D); // Ensure range is [-32 * D, 32 * D]
+ assert(abs(32 * D) < INT16_MAX); // Ensure we don't overflow
+
+ entry += bonus * 32 - entry * abs(bonus) / D;