有趣的象棋残局

IG

It's equivalent to 3 piles of stones (or matches): 1,4,6. While "1" (the pawns) can't be moving backward, the "4" and "6" (the cannons) can be increased in a certain situation (by moving backward) to a certain upper bound. However, I believe, the principle still applies. Therefore, "cannon 7 up 1" is the critical move, the 3 piles now become 1, 4, 5. If the black cannon comes forward, it will either become 1,4,0 or 1,0,5. The next move red has to make is turn it to 1,1,0 or 1,0,1. Black is end played, whether black moving pawn forward or the the cannon forward by 1 step or moving the other cannon backward won't help.www.ddhw.com