50. model mate, by the chariot

Helpmates in xiangqi

4 moves

Black moves first and both sides cooperate: Black, Red, Black, Red, and Red's second move mates. Black has 56 legal first moves and exactly one of them works. 10 pieces, Black 28 to Red 13 in material, mate by the chariot. Themes: pure mate, model mate, the general walks in, a qu…