What do 五七炮, 五八炮 and 五六炮 mean in the Central Cannon?
These answers restate the rules implemented by our open-source engine, which follows the WXF laws for movement, checkmate and both repetition rulings: a side that forces a repetition by perpetual check or perpetual chase loses rather than drawing. The chase half has not been validated against the official casebook. Where an answer refers to a specific position, that position lives on the linked reference page, where the build verifies it before publishing.
Direct answer
The numbers are file numbers for Red's two cannons. In every one of these systems the first cannon stands on the central fifth file; the second number says where the other cannon stands. 五八炮 leaves it on its home file, 五七炮 moves it to the seventh file (炮八平七) and 五六炮 to the sixth (炮八平六). They are the main families of Central Cannon play against Screen Horses.
How to read the names
Red counts files from its own right, one to nine. The cannons start on files two and eight, so after the usual first move 炮二平五 one cannon is central and the other still sits on eight. The name of the system is a snapshot of where both cannons end up, not a move order: 五七炮 simply means "cannons on five and seven".
The same convention explains other names you will meet, such as 五九炮, where the second cannon goes all the way to the edge file. Once you can read notation, you can decode any of these names in a second.
What the second cannon's file changes
The second cannon decides two things: which of Black's pieces it bears down on, and which route Red's left chariot uses.
- 五七炮 puts the cannon on the file where one of Black's horses usually stands, so it adds pressure to that wing. Moving the cannon off file eight also lets the left chariot step onto that file.
- 五六炮 brings the second cannon next to the centre, a more compact setup that keeps both cannons close to the palace and also frees file eight for the chariot.
- 五八炮 keeps the cannon on its home file, usually to use it further up that file; the left chariot then needs another way out.
Which one to learn
All three are established systems played at every level, and none is refuted. Pick one and learn its plan: which Black piece you are pressing, where your chariots go, and what Black's usual counterplay looks like. Knowing why the cannon stands where it does is worth more than a long list of moves, and the Central Cannon page is the place to start.
Related questions
Is 五九炮 the same kind of name?
Yes. The second cannon goes to the ninth, edge file. It is often seen alongside the crossing-chariot lines.
Do beginners need these names?
Not to start playing. They become useful once you read opening material or annotated games, because they tell you instantly what kind of middlegame is coming.
Does Black have similar names?
Black's setups are usually named by the defence as a whole, such as Screen Horses, rather than by cannon files. The file-number habit is mainly used for Red's Central Cannon systems.
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