What should Black play against the Central Cannon?
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
Screen Horses — 馬8進7. It defends the threatened central soldier and develops a piece, which is exactly what every other reply fails to do. The alternative is a central cannon of your own, giving 順炮 or 列炮 depending on which side it comes from.
Why passive defences fail
The natural beginner reply is to defend the soldier with something that does nothing else — an advisor, or a second soldier move. Those defend but cost a tempo, and against a Central Cannon a tempo is what the whole opening is about. Several moves later Black is defending with one fewer developed piece and it does not get better.
The counterattacking option
Answering a central cannon with your own turns the game around: Black becomes an attacker too. It is sharper and requires more precise calculation, since every tactic is mutual and Red's extra move decides who gets there first.
Related questions
Is Screen Horses hard to learn?
No — the first few moves are natural and the plans are clear. It is the standard recommendation for a reason.
Can I just ignore the threat?
No. Losing the central soldier opens the file toward your own general.
.