Turtle Back and Mandarin Duck Cannons in Xiangqi

The Turtle Back Cannon

The main line is 1.炮二平五 马8进7 2.马二进三 车9进1 3.车一平二 炮8退1. In words: Black answers the Central Cannon by developing the left Horse. After Red's right Horse comes out, Black lifts the corner Chariot one point to its second rank. Red develops the right Chariot to file two, and Black pulls the left Cannon back one point, so it stands on the second rank right next to the raised Chariot.

Chinese writers say the resulting shape looks like a turtle's back, hence the name. The idea is old. The late Qing player Ba Jiren (巴吉人) wrote a manual, known today as 反梅花谱 (the Anti-Plum Blossom Manual), which argued that the Central Cannon could beat the classic Screen Horses and proposed other setups for Black instead. Turtle Back Cannon games were among them.

What does the retreat achieve? The Cannon is safe on its new point: Red's Chariot on file two can reach it, but the raised Chariot beside it would recapture. And while the Cannon sits there, that Chariot cannot slide along the second rank at all; the engine shows it can only step one point forward or back. So the next move is planned in advance. The Cannon moves off sideways, to file five, three or one depending on Red's setup, and that clears the rank for the Chariot to follow it across.

Each of these starts from the same three moves: 4.兵五进一 炮8平5 meets a central Soldier push with a central Cannon, 4.马八进七 炮8平3 points the Cannon at Red's left wing, and 4.炮八进二 炮8平1 takes it to the edge. The Chariot then follows along the rank, as in 1.炮二平五 马8进7 2.马二进三 车9进1 3.车一平二 炮8退1 4.兵七进一 炮8平3 5.马八进七 象3进5 6.马七进六 车9平4, where it arrives on Black's fourth file.

Published analysis tests six Red replies at move four and singles out 4.马八进七, developing the left Horse toward the center, as the most effective. It keeps every option open, whether a central Soldier push, a river-bank Cannon or a crossing Chariot, while Black's pieces are still finding their places.

A Turtle Back trap to know

One line from that analysis shows how quickly things can go wrong: 1.炮二平五 马8进7 2.马二进三 车9进1 3.车一平二 炮8退1 4.马八进七 炮8平3 5.兵五进一 炮2平5 6.车二进六 卒7进1 7.车二平三 车9进1 8.炮八进五 马2进3. Red pushes the central Soldier and Black answers with a central Cannon. Red's Chariot crosses the river and moves onto Red's third file, and Red's left Cannon jumps deep into Black's camp, onto the rank where Black's Cannons started, lining up along it through Black's central Cannon. The analysis treats 8...马2进3, developing the last Horse, as Black's only sensible reply.

The tempting alternative is 8...炮3平7, swinging the other Cannon across so that it hits Red's Chariot through Black's own Horse. It fails to 9.车三进一, when the Chariot simply takes that Horse. If Black then grabs a Soldier with 9...炮5进3, 10.炮五进四 takes the central Soldier and lines Red's Cannons up for a double-cannon mate (重炮) down the middle. The full line is 1.炮二平五 马8进7 2.马二进三 车9进1 3.车一平二 炮8退1 4.马八进七 炮8平3 5.兵五进一 炮2平5 6.车二进六 卒7进1 7.车二平三 车9进1 8.炮八进五 炮3平7 9.车三进一 炮5进3 10.炮五进四.

The analysis calls it an immediate win for Red. Our engine check agrees on the essentials: 31 of Black's 33 legal replies allow mate in one, and the two that do not, 马2进3 and 将5进1, leave Black a Horse down.

The Mandarin Duck Cannons

The basic position comes from 1.炮二平五 马2进3 2.马二进三 卒7进1 3.车一平二 车9进2. In words: Black develops the right Horse first and pushes the seventh-file Soldier, and after Red's Chariot comes to file two, Black lifts the corner Chariot two points so it stands on the Cannons' starting rank, right beside Black's left Cannon. ECCO allows the third-file Soldier push instead of the seventh, and the two versions are usually called the 7-pawn and 3-pawn Mandarin Duck.

The name pictures the two Cannons working as a pair, like mandarin ducks, the classic Chinese image of a couple that is never apart. The point of the odd Chariot move is a little hidden. At the moment, Black's left Cannon stands on the file of Red's Chariot, and it is guarded by Black's other Cannon, which can jump over the right Horse along the rank. Black's plan is to pull that right Cannon back with 炮2退1 and slide it across behind its partner, and as soon as it leaves the rank, the left Cannon loses its guard. The engine confirms that after 3...炮2退1 straight away, Red's Chariot could take the left Cannon for nothing. So the Chariot steps up first and takes over the guarding job.

Here is the full formation in the 3-pawn version found in Chinese opening primers: 1.炮二平五 马2进3 2.马二进三 卒3进1 3.车一平二 车9进2 4.马八进七 炮2退1 5.炮八进二 炮2平8. Black's right Cannon drops back one point and travels most of the way across the board along the second rank, and now the two Cannons stand one behind the other on the same file. The rear Cannon can jump the front one, and in this position it is attacking Red's Chariot on file two.

How Red meets the Ducks

Published analysis of the 7-pawn version looks at four Red options at move four, and two of them are worth knowing. 4.炮八平六 puts the left Cannon on the palace corner. If Black now retreats the right Cannon, Red's Cannon can run straight up the open sixth file into Black's camp and stand in its way: after 1.炮二平五 马2进3 2.马二进三 卒7进1 3.车一平二 车9进2 4.炮八平六 炮2退1 5.炮六进六, the slide 炮2平8 is no longer legal, and no Black piece can take Red's Cannon at once.

The analysis rates 4.炮八进二 as Red's strongest try. The left Cannon rises to Red's river bank, where it threatens to swing out to the edge file and hit Black's raised Chariot. Black spends a move on the edge Soldier to cover that point, and Red pushes the central Soldier: 1.炮二平五 马2进3 2.马二进三 卒7进1 3.车一平二 车9进2 4.炮八进二 卒9进1 5.兵五进一 炮2退1 6.炮八平七 马8进7 7.兵五进一. Red's Cannon first moves across to hit Black's right Horse, the central Soldier keeps marching, and Black's paired Cannons never get coordinated.

A Mandarin Duck slip

The Mandarin Duck is built to set traps, but a typical Black error is running the plan too early. In 1.炮二平五 马2进3 2.马二进三 卒7进1 3.车一平二 车9进2 4.马八进七 炮2退1 5.车二进六, the correct move is 5...马8进7, developing first. The hasty 5...炮2平7, swinging the Cannon across at once, runs into a central Soldier storm: 1.炮二平五 马2进3 2.马二进三 卒7进1 3.车一平二 车9进2 4.马八进七 炮2退1 5.车二进六 炮2平7 6.兵五进一 卒7进1 7.兵五进一 士4进5 8.兵五进一 卒7进1 9.马三进五 炮7进8 10.仕四进五. Black's Cannon does reach Red's back rank and take an Elephant, but it is alone there, and the analysis rates Red's central attack clearly better.

Choosing between them, and facing them

Both systems are for players who want to take an opponent out of familiar territory. The Turtle Back Cannon is built for gathering force on one wing and counterattacking, and Chinese commentators name its weak point as slow, roundabout development. The Mandarin Duck is more of a trap-setter, and its weakness is congestion: with a Chariot and two Cannons crowded onto one wing, a badly handled Duck formation ends up with its own pieces in each other's way.

As Red, the practical advice from the published analysis is consistent. Develop normally, get the left Horse or Cannon working early, and push the central Soldier while Black's pieces are still sorting themselves out. Sensible development is rarely punished in either line; moves made on autopilot often are.

Try both as surprise weapons against the XiangqiPlay computer, which offers eight levels from Easy to God with a free account, before you spring one on a friend. And if a Turtle Back game ends in a mating attack, the 5,000 engine-proven puzzles at /puzzles are a good place to sharpen exactly that skill.