91. pure 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 46 legal first moves and exactly one of them works. 17 pieces, Black 40 to Red 15.5 in material, mate by the chariot. Themes: pure mate, Black blocks its own general, the ge…