The Screen Horses

What do the two horses guard?

Red's first move, 炮二平五 (C2=5), aims the cannon at the soldier on e6, and the screen horses answers by guarding that soldier with both horses. Black brings one horse from h9 to g7 with 马8进7 (H8+7) and, on Black's third move, the other from b9 to c7 with 马2进3 (H2+3). The horse on g7 guards e6 through its leg on f7, and the horse on c7 through its leg on d7.

Of the openings that can follow the central cannon and Black's horse reply, the screen horses is the most common. It is a solid opening. The advisors and elephants guard the palace, and the two horses protect the centre soldier, because losing that soldier would put the general at risk. The opening also has many variations, which is one reason more and more players choose it.

The course line, move by move

The walkthrough below plays the first twelve moves, six for each side, of the line that the opening course on Xiangqi Arena teaches. The line starts with the standard moves of the screen horses, and a computer engine continued it from there. Its first nine moves also begin the archive's most played twelve-move line of the screen horses, which 925 games follow and the first card below shows. The two lines part at Black's fifth move: the course line plays 士6进5 (A6+5), and the archive's line plays 炮8平9 (C8=9).

Black completes the screen horses in the first six moves, while both sides bring a chariot to the h-file. Each side then pushes a soldier, Red's from c3 to c4 and Black's from g6 to g5. Red's chariot crosses the river to h6 and attacks the cannon on h7. Black then moves an advisor to e8, Red brings the left horse out to c2, and Black's cannon goes to the edge at a7.

Start by learning these twelve moves. The Learn section on Xiangqi Arena has a drill in which you play Black's side of the screen horses move by move. After that, try the defence in a few games against the computer.

Red's choices in the archive

The board below starts after Black's third move, with both horses out. Its arrows show the three moves Red played most often there: 兵七进一 (P7+1), 兵三进一 (P3+1) and 马八进九 (H8+9). Each arrow carries its share of the 4,147 games that reached the position.

The cards under the board are named lines from the archive. The first two continue with 兵七进一 and lead to two of Black's answers to the river-crossing chariot, 车二进六 (R2+6). The third plays 车二进四 (R2+4) at once, a move that is not among the three on the board. The fourth continues with 兵三进一 and turns into the five-seven cannons.

What comes after the two horses?

Once both horses are out, Black's next task is to free them. Players usually choose 卒7进1 (P7+1) or 卒3进1 (P3+1), which make the horses more flexible, and after the chariots come out, the cannons also get more room. After Black's third move, the soldier on g6 stands on the leg of the horse on g7, and the soldier on c6 on the leg of the horse on c7. Each soldier move lets one horse jump forward.

Red, meanwhile, mostly advances the chariot four or six points, often across the river. Black then usually answers with one of three moves: 炮8平9 (C8=9), which moves the cannon aside to offer an exchange of chariots; 马7进6 (H7+6), the left horse to the river; or 车1进1 (R1+1), the horizontal chariot.

The board below plays the course line up to Red's 车二进六 (R2+6) and shows these three answers as arrows. The course line itself continues with 士6进5 (A6+5), and the archive's lines with 炮8平9 and 马7进6 are the first two cards above. If you are happy to trade chariots early, the cannon move suits you. If you want a piece in play at once, choose the horse move: from f5 the horse attacks the soldiers on e3 and g3.

The opening codes show how much ground this defence covers. The ECCO, a code list of xiangqi openings, gives its whole class C, from C00 to C99, to the central cannon against the screen horses. Within that class it numbers Red's systems: the five-six cannons take C50 to C56, the five-seven cannons C60 to C78 and the river-patrol cannon C81 to C86.

Common mistakes

A common mistake is to bring out one horse and leave the other at home. With only 马8进7 (H8+7) played, the soldier on e6 has a single guard, and the wing of the horse on b9 falls behind. The whole defence rests on two guards for the centre soldier, because losing that soldier would put the general at risk. Play 马2进3 (H2+3) early, as the course line does on Black's third move.

Another mistake is to leave the chariots in their corners while the other pieces come out. In the course line, Red's chariot comes to h0 early and attacks the cannon on h7 up the open file. Black's chariot is already on h9, the point the horse left, so the cannon has a guard; from the corner, the chariot could not give it one. Bringing the chariots out early is the first of the five opening principles.

A third mistake is to leave the soldiers on g6 and c6 where they started. Each stands on the leg of a horse, so neither the horse on g7 nor the horse on c7 can jump forward. Once both horses are out, play 卒7进1 (P7+1) or 卒3进1 (P3+1). The course line pushes the soldier on g6 to g5, and the horse on g7 can then reach f5 or h5.

The screen horses in the archive

In the 10,148 games with the screen horses, Red won 35% and Black 28%, and 37% were drawn. Across all 29,164 games between human players in the archive, Red wins 37% and 36% end in a draw. Games with this defence last 43 moves on average.

As Black, Lü Qin played the screen horses in the most games, 365, and Xu Yinchuan has the best score with it, 62.1% from 265 games. On the Red side, Lü Qin played the most games against it, 382, and Xu Yinchuan scored best, 70% from 200 games. You can find their games in the archive and replay them move by move.

From the Kangxi era to modern research

Before the Qing dynasty, players mostly played the central cannon, and the screen horses was devised in the Kangxi era of the Qing. 王再越 (Wang Zaiyue), who lived in that era, studied the screen horses against the central cannon in his manual 梅花谱 (Meihuapu). One of its chapters has eight games in which the screen horses, as the second player, beats the central cannon. The manual circulated in handwritten copies until a lithographed edition appeared in 1917 and a printed edition in 1926.

In modern times, the research of 谢侠逊 (Xie Xiaxun), 胡荣华 (Hu Ronghua) and others made the screen horses the most used of the four great defences. The other three are the same-direction cannons, the counter-palace horse and the single horse defence. The screen horses will not win games by itself, but it gives you a reliable way to meet the central cannon.