The Same-Direction Cannons

What do the two cannons attack?

Black brings a cannon to the centre as well, so both sides start with the same threat. Each cannon attacks the other side's centre soldier over its own: Red's cannon on e2 attacks e6 over e3, and Black's cannon on e7 attacks e3 over e6. This strong mutual attack is the main feature of the opening.

This opening is one of the four great defences, the four common openings that the second player generally uses against the central cannon. Like the opposite-direction cannons, it is a cannon-fight opening (斗炮局, doupaoju), in which Black's central cannon aims to balance Red's. The ECCO, a code list of xiangqi openings, puts both cannon fights in its class D, with the same-direction cannons at D00 to D29.

Red has many ways to go on from here, for example 马二进三 (H2+3), 兵三进一 (P3+1), 炮八平六 (C8=6) and 炮八进四 (C8+4). Most players today pair the opening with 马二进三 and 车一平二 (R1=2), and the walkthrough below plays those two moves as Red's second and third.

The course line, move by move

The walkthrough plays the line that Xiangqi Arena's opening course teaches. It starts with the two moves that define the opening, a computer engine continued it from there, and the board shows its first twelve moves, six for each side. In the archive, 111 games follow it for all twelve moves, more than any other twelve-move line of this opening.

The first eight moves are the line of the first card below, the straight chariot against the horizontal chariot. Red's chariot comes to h0 on the open h-file. Black lifts a chariot to i8 and swings it across to d8, where it attacks Red's advisor on d0.

In the last four moves, Red pushes the soldiers on g3 and c3 so that both horses can jump forward, and Black brings out the second horse to c7. Black's last move lifts the other chariot to a8, where the two chariots guard each other along rank 8.

The opening course has a drill for each side of this line. Play it as Red and as Black until the moves come easily, then try the opening in a game against the computer.

Straight or horizontal chariot?

The board starts after both sides have brought out a horse, a position that 1,686 games in the archive reached. It shows the three moves Red chose most often there, each with its share of those games.

Two of the three are chariot moves, and they name the cards below. 车一平二 (R1=2) puts the chariot on the open h-file, the straight chariot, and 车一进一 (R1+1) lifts it to i1, the horizontal chariot. In the first two cards Red plays the straight chariot, and Black answers with a horizontal chariot or keeps both chariots at home. In the third card the roles are reversed.

An active chariot and a trap on e6

This opening is an active, attacking way to play, and its follow-ups change with the opponent's moves. Its first rule is an old maxim, 顺手炮，先要活车 (shunshoupao, xian yao huo ju): in the same-direction cannons, first make the chariot active. The maxim comes from the 全旨 (Quanzhi) section of the Ming manual 橘中秘 (Juzhongmi). The walkthrough follows it on both sides: Red's chariot reaches the open h-file on Red's third move, and Black's rises to i8 on Black's third and crosses to d8 on the fourth.

The opening also has a beginner's trap on the centre soldier. Red's cannon can take the soldier on e6 with check as early as the second move. If Black answers correctly, the capture holds back the development and coordination of Red's pieces. Black gets a chariot out before Red does, and with the centre soldier gone, Black's horses can occupy the centre.

The board below plays the trap. Red's 炮五进四 (C5+4) takes the soldier on e6 with check, because Black's own cannon on e7 is the screen between Red's cannon and the general. Black blocks with 士4进5 (A4+5), which puts a second piece on the file, so the cannon no longer gives check.

After 马二进三 (H2+3) and 马8进7 (H8+7), the horse on g7 attacks the cannon, which nothing guards, and the cannon retreats to e4 with 炮五退二 (C5-2). Black's chariot then comes to h9 with 车9平8 (R9=8), while both of Red's chariots are still at home.

Common mistakes

Taking the centre soldier with the cannon is the trap shown above. Red's 炮五进四 (C5+4) wins the soldier on e6 with check, but after 士4进5 (A4+5) and 马8进7 (H8+7) the cannon is attacked and retreats to e4. By then it has made three of Red's first four moves, and both of Red's chariots are still at home. A soldier is worth little this early, and every move you spend winning it is a move your other pieces do not get.

Another mistake is to leave the chariots at home for too long. At the start they stand on poor points, and the old rule of this opening is to make the chariot active first. In the walkthrough Black's chariot attacks the advisor on d0 by Black's fourth move, and in the third card Red's chariot does the same to the advisor on d9. If your chariots are still in the corners by then, the other side's chariot has the open files to itself.

The last mistake is to develop one wing only. The first horse and chariot come out on the same side of the board, and it is tempting to keep playing there. In the walkthrough the second horse soon follows, to c2 for Red and to c7 for Black, and each gives its own centre soldier a second guard. A wing that falls behind can come under attack, so keep both wings moving at a similar pace.

The same-direction cannons in the archive

In the 2,274 games with the same-direction cannons, Red won 44%, Black won 29%, and 27% were drawn. Across all 29,164 games between human players in the archive, Red wins 37% and 36% end in a draw, so you can compare this opening with the archive as a whole. A game with this opening lasts 42 moves on average.

As Red, Lü Qin has the best score against this defence: 76.8% from 56 games. As Black, Hu Ronghua played it in the most games, 69, and Hong Zhi scored best with it, 59.7% from 31 games. You can look up these players in the archive and replay their games move by move.

In the classical manuals

Players have studied this opening for centuries. The Ming manual 橘中秘, written by 朱晋桢 (Zhu Jinzhen), is an important classic of the central cannon, and its study of the same-direction cannons goes especially deep. It is one of the two famous manuals, named together with 梅花谱 (Meihuapu) as 橘梅 (jumei).

梅花谱, the Kangxi-era manual of 王再越 (Wang Zaiyue), gives the opening two chapters of five games each, both played from the first player's side. In one the straight chariot beats the horizontal chariot, and in the other the horizontal chariot beats the straight chariot. These are the same pairings as the first and third cards above.

Among modern masters, 胡荣华 (Hu Ronghua), who won the national title ten times in a row from 1960 to 1979, is known for his skill in this opening. This guide will not make you play like him, but the course line is a good place to start.