How do you checkmate with two cannons alone, no other pieces?
These answers restate the rules implemented by our open-source engine, which follows the WXF laws and is regression-tested against the official 110-diagram repetition casebook. Where an answer refers to a specific position, that position lives on the linked reference page, where the build verifies it against the engine before publishing.
Direct answer
Two cannons can force mate against a bare general, and the technique is essentially the double cannon pattern, 重炮, applied from a bare endgame: stack them on the same file or rank so the front cannon screens for the rear one, bring your own general up to deny the escape file, and drive the enemy general into a corner where the stacked line covers every remaining point.
Why two cannons succeed where one cannot
A lone cannon cannot even check a bare general, since it has nothing to jump. Two cannons solve that problem for each other: once stacked on the same line, the front cannon becomes the rear cannon's screen, exactly as in 重炮, and a blocking piece interposed by the defender simply becomes a new screen rather than a defence.
Getting them coordinated first
The harder part is manoeuvring both cannons onto the same open line in the first place, since a bare general has no pieces to help you get there and none to hinder you either. Bring your own general up early to hold the escape file, exactly as with a lone chariot mate, then walk both cannons onto the same line before committing to any checks.
Related questions
Is this listed in the standard minimum-material table?
It sits alongside the combinations in minimum material to win, forcing mate the same way horse-and-cannon or two horses do.
Does the defender's own general ever get in the way of this mate?
Rarely; with no other material on the board, the defending general's own movement does not obstruct the attacker's cannons the way a horse's leg can be blocked.
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