The Central Cannon

What does the first move attack?

The first move points a cannon at the middle of Black's position. It goes from h2 to e2, the centre file, which each side counts as its fifth. From there its line runs up the file, over Red's own soldier on e3 as the screen, to Black's soldier on e6. At the start of the game, no Black piece guards that soldier.

A cannon on the fifth file threatens the opponent's fifth-file soldier and the palace behind it, which makes the central cannon a strongly attacking way to open. Red plays it more often than any other opening. Its weak spot lies on Red's own side: the third or the seventh file of Red's bottom rank is easy to attack.

The most common reply brings out the horse on the same flank. The two moves together are known by a rhyme, 当头炮，马来跳 (dangtoupao, ma lai tiao): meet the central cannon by jumping out a horse. On the board that horse goes from h9 to g7, where it guards e6 through its leg on f7.

From there the game can turn into many openings. The most common is the screen horses (屏风马, pingfengma), in which Black's other horse also comes out to guard the centre soldier.

The four great defences (四大布局, sida buju) are the same-direction cannons, the screen horses, the counter-palace horse and the single horse defence. They are the common openings that the second player generally uses against the central cannon. Black has other choices too, among them the opposite-direction cannons and 鸳鸯炮 (yuanyangpao).

The course line, move by move

The board below plays the line that Xiangqi Arena's opening course teaches. It starts with the central cannon's standard moves, a computer engine continued it from there, and the board shows the first twelve moves, six for each side. In the archive, 925 games follow it for all twelve moves, more than any other twelve-move line of this opening.

Black answers with the screen horses, so by Black's third move two horses guard the soldier on e6. Both sides bring a chariot to the h-file, then push a soldier on opposite wings: Red's from c3 to c4 and Black's from g6 to g5.

Red's chariot then crosses the river to h6 and attacks the cannon on h7. When the cannon steps aside to i7, the chariots on h6 and h9 attack each other along the file. The line ends with Red's chariot on g6 and Black's cannon drawn back to i8.

The first card under Black's answers gives the same twelve moves with their results. Once you know the moves, practise them in the opening course, where you play both sides of the line yourself.

Black's answers in the archive

The board starts after 炮二平五 (C2=5) and shows the three answers that Black played most often: 马8进7 (H8+7), 马2进3 (H2+3) and 炮8平5 (C8=5). Each one is marked with its share of the 17,286 games that reached this position.

The cards below are named lines from the archive, and each continues from this position with one of these answers. The first and the fourth continue with 马8进7, the second with 马2进3, which leads into the counter-palace horse, and the third with 炮8平5, the same-direction cannons. The fourth turns into the opposite-direction cannons later, when Black plays 炮2平5 (C2=5) on Black's fourth move.

If you are learning to meet the central cannon as Black, start with 马8进7 and the screen horses. It is the answer that Black plays most often, and the course line is built on it. As Red, prepare for all three answers, because each one leads to a different opening.

The centre and the five principles

Attacking and defending the centre, above all the centre soldiers, is a common theme of the opening, and it is the idea behind the central cannon openings. Usually at least one horse should come toward the middle to defend the centre soldier. In the course line both of Black's horses do so by Black's third move, from g7 and c7.

Five principles sum up good opening play: bring the chariots out early, do not move one piece again and again, do not grab soldiers in the opening, keep both wings balanced and keep the general safe. The course line follows the first one, since each side has a chariot on the h-file by its third move. The third bears on the centre soldier, as the next section shows.

Use the principles as a checklist when you look back over a game. After a game against the computer on Xiangqi Arena, go through all five and look for the first one you broke.

Common mistakes

As Black, do not leave the centre soldier without a guard. Red's cannon threatens the soldier on e6 and the palace behind it from the first move, and at the start nothing guards that soldier. If your first moves ignore the centre, the cannon can take it and stand right in front of your palace. That is why the most common reply, 马8进7 (H8+7), guards e6 at once.

As Red, do not grab the centre soldier when Black answers with a cannon of its own on the centre file. The soldier on e6 then has no guard and looks free, but taking it with the cannon is a beginner's trap. If Black answers correctly, the capture holds back the development of Red's pieces and the way they work together. Your cannon has moved twice to win one soldier while the horses and chariots are still at home.

Whichever side you play, do not leave the chariots in their corners. In the course line each side has a chariot on the h-file by its third move, as the first principle asks. Red's first move emptied h2, so from h0 the chariot attacks the cannon on h7 at once, and Black's chariot on h9 is there to guard it. A chariot left in its corner can do neither job.

The central cannon in the archive

The archive shows how the opening scores in practice. Of its 17,286 central cannon games, Red won 37% and Black 28%, and 35% were drawn. For comparison, over all 29,164 games between human players, Red wins 37% and 36% end in a draw. A central cannon game lasts 43 moves on average.

As Red, Lü Qin played the central cannon in the most games, 600, and Xu Yinchuan has the best score with it, 71.5% from 286 games. Against it as Black, Hu Ronghua played the most games, 472, and Xu Yinchuan scored best, 60.9% from 376 games.

You can browse the archive by opening or by player and replay each game move by move. Once the course line feels familiar, watching strong players handle the positions that follow is a good next step.

The central cannon in the classical manuals

Players have studied the central cannon for centuries. 橘中秘 (Juzhongmi), a xiangqi manual of the Ming dynasty by 朱晋桢 (Zhu Jinzhen), is known for its study of this opening. It is one of the two famous manuals, and together with the other, 梅花谱 (Meihuapu), it is called 橘梅 (jumei).

梅花谱 is the work of 王再越 (Wang Zaiyue), who lived in the Kangxi era of the Qing. Its date is unknown. Under the Qing it circulated only in handwritten copies, until a lithographed edition came out in 1917 and a printed edition in 1926.

梅花谱 makes special studies of the same-direction and opposite-direction cannons, the palace-corner cannon and the screen horses against the central cannon. Among its chapters are the screen horses beating the central cannon, in eight games, and the central cannon beating the opposite-direction cannons, in five.

Much later, in 2004, the ECCO, the Chinese numbering of xiangqi openings, sorted openings into five classes from A00 to E99. Nearly half of its codes, B00 to D55, are central cannon openings. The central cannon will not win games by itself, but it gives Red a clear target from the first move.