The Five-Seven Cannons

How the system works

Red sets up the two cannons so that each one attacks a Black soldier. The system starts with 炮二平五 (C2=5), which takes the first cannon to e2 on the fifth file, where it attacks Black's soldier on e6. Both sides then develop, Red with a horse and a chariot and Black with both horses and a chariot. On Red's fourth move, 炮八平七 (C8=7) takes the second cannon from b2 to c2 on the seventh file.

The board in this section draws both lines of attack. The cannon on e2 attacks the soldier on e6 through Red's soldier on e3, and the cannon on c2 attacks the soldier on c6 through the soldier on c3. From c2 the second cannon also guards the horse on g2 along rank 2, using the cannon on e2 as its screen.

The central cannon can turn into the five-seven cannons whether Black answers with the screen horses (屏风马, pingfengma) or with the counter-palace horse (反宫马, fangongma). The ECCO, a code list of xiangqi openings, gives each form its own range: C60 to C78 against the screen horses and B50 to B56 against the counter-palace horse.

The course line, move by move

The board below plays the line that the site's opening course teaches for the five-seven cannons. It begins with the system's standard moves, and a computer engine continued it from there. You can step through its first twelve moves, six for each side, with a note on each. In the course, two drills follow the same line: in one you play Red's moves, and in the other you defend against them as Black.

Red completes the five-seven set-up on its fourth move, then brings out the second horse and the second chariot. Black's soldier on c6 steps to c5, where the cannon on c2 still attacks it. On the last move Black's cannon advances to b3 and attacks Red's soldier on e3, and Red's chariot on b0 attacks the cannon in turn.

Lines from the archive

The board in this section starts from the course line's position after Red's sixth move, with one change in Black's soldier move: 卒7进1 (P7+1) on the g-file in place of the course line's 卒3进1 (P3+1) on the c-file. In the archive, 649 games reached this position. The arrows show Black's three most common replies there, and all three are cannon moves.

Of the four lines below, the second and third continue with the two most common replies, 炮2进4 (C2+4) and 炮8进4 (C8+4). The first reaches the five-seven set-up by another order of moves, and the fourth is the system against the counter-palace horse. If your opponents meet the central cannon with the screen horses, study the first three lines; if they play the counter-palace horse, start with the fourth.

The opening principles in this line

Five principles help you judge any opening line: bring the chariots out early, do not move one piece again and again, do not grab soldiers, keep both wings in balance, and keep the general safe. The course line for the five-seven cannons keeps to all five.

Four of them show in the moves themselves. All four chariots leave their corners within the twelve moves, Black's on its second and fifth moves and Red's on its third and sixth, and no piece moves twice. Red develops a cannon, a horse and a chariot on each wing, and both generals stay on their starting points.

The third principle shows in a move Red does not make. From Red's fourth move, the cannon on c2 attacks Black's soldier, first on c6 and then on c5, yet Red leaves it alone and brings out the edge horse and the second chariot. No piece is captured in the twelve moves.

Common mistakes

The first mistake is taking the soldier on e6 with the central cannon. The cannon attacks that soldier from the first move, so the capture can look free. But Black's horse on g7 has guarded it since Black's first move, and after Black's third move both horses do. The horse takes back, and Red has given a cannon for a soldier.

The second is grabbing the soldier in front of the second cannon. From Red's fourth move the cannon on c2 attacks Black's soldier on c6, and it still attacks it after the soldier steps to c5. Taking it breaks two principles at once: the cannon moves a second time, and a move goes on a soldier while the horse on b0 and the chariot on a0 are still at home. The course line leaves the soldier alone and develops both pieces with 马八进九 (H8+9) and 车九平八 (R9=8).

The third is leaving the second chariot in its corner. Moving the cannon from b2 to c2 clears the b-file for that chariot, and in the course line it comes to b0 on Red's sixth move. From there it attacks Black's cannon on b7, and again on b3 when that cannon advances to attack the soldier on e3. A chariot left on a0 does neither, and Red's two wings fall out of balance.

How does it score in the archive?

In the archive's games with the five-seven cannons, Red won 36%, 38% were drawn and Black won 26%. A game lasted 44 moves on average. For comparison, Red wins 37% of all 29,164 human games in the archive, and 36% end in a draw.

As Red, Lü Qin has played the system most often, in 159 games, and Xu Yinchuan has the best score, 67.9% over 78 games. As Black, Lü Qin has the most games, 130, and Xu Yinchuan the best score, 62.5% over 104 games.

At the end of this section you can replay one archive game with the system, move by move. When the course line feels familiar, try the set-up as Red in a few games against the computer. The system will not win games by itself, but it gives both cannons a target early.