Tiger Silhouette Checkmate in Xiangqi: The 侧面虎 Mate

Why a tiger, and why from the side

侧面 means the side, or the profile view of something, and 虎 is tiger, so the Chinese name is roughly tiger seen from the side. Xqinenglish, which uses the English name Tiger Silhouette, credits that translation to Felix Tan. Chinese books also call the Horse in this mate 高钓马, the high angler horse, because it stands one rank further from the enemy's back rank than the angler horse of 钓鱼马.

Whatever image lies behind the tiger, the English name is a handy reminder of where the attack comes from: the side of the palace, not the front.

Naming varies a little between books, and a few use one name for both angler points. Most basic-mate books keep them apart, which is the convention used here and in our angler horse guide.

Where the Horse stands and what it covers

Read the board from Red's side, with Black's palace at the top. Black's Soldiers start on the fourth rank from Black's edge, the soldier rank. The tiger point is on that rank, on the third file in from either edge, the same point where a Black Soldier stands at the start of the game.

From the right-hand tiger point, a Horse reaches two palace points: the middle of the palace's right edge and the middle of its front edge. The leg for the first is the point directly in front of the Horse. The leg for the second is the point beside it on the inside, directly in front of the palace's front-right corner.

Those two palace points are the only neighbours of the front-right corner. So if the General stands on that corner, the Horse has taken both of its moves, and a check along the rank or the file through the corner is mate. If the General is on the middle of the right edge, the Horse's arrival is itself a check, and once the centre is covered and the back corner is blocked, the only way out is up the file to the front corner, straight into the net. In practice the General is usually confined to that one file.

A two-move example

Black's General has been driven to the middle of the palace's right edge, and both Black Advisors are still on their back corners. Red has a Horse on its own side of the river, on the rank next to the river and the second file from the right edge, a Chariot on the central file on the same rank, an Advisor in the centre of its own palace, and its General at home. Red to move.

There is no mate in one here; XiangqiPlay's rules engine checked every Red move. So the Horse leaps across the river to the right-hand tiger point, and that is check. The General cannot go back to the corner, where its own Advisor stands, and it cannot step left into the palace centre, which lies on the Chariot's file. Its only legal move is up the file to the front-right corner.

Now the net closes. The Chariot climbs the central file to the middle of the palace's front edge, right beside the General. The Horse guards it, so the General cannot capture, and the Horse also covers the middle of the right edge behind the General. Checkmate. Stepping the Chariot across to the right rib file and checking straight up it works too, since both of the General's neighbours belong to the Horse.

The Red Advisor matters more than it looks. Without it, the Chariot could check up the right rib file at once, with the Red General covering the palace centre along the open file, and that would be a different mate altogether. And if Black's right Advisor were missing, the Horse check could simply be answered by the General retreating into the empty back corner.

Finishing along the rank

The final check doesn't have to come up the file. Put Black's General on its front-right corner with both Advisors at home, a Red Horse already on the tiger point, and a Red Chariot on the right edge file on Red's side of the river. The Chariot runs up the edge to Black's third rank and checks along it. Both escape points belong to the Horse, and no Black piece can step onto the points in between, so it is mate. Without the Horse, the same check is answered by the General retreating to the middle of the right edge.

How it fits with the other horse mates

Seen from one side of Black's palace, the Horse's attacking posts form a small family. On Black's second rank sit the trough point and, further out, the golden hook point. On the third rank is the angler point, and on the soldier rank the tiger point. Each covers a different pair of palace points, so each needs a different partner. The angler Horse takes the back corner and the centre; the tiger Horse takes the middle of the side edge and the middle of the front edge.

That is why it pays to know them as a set. When a Horse lands near the palace, ask which two points it controls, where the General can still go, and which of your pieces can check it there.

Defence, and the attacker's usual slips

Defence starts with the legs. A piece directly in front of the tiger Horse cuts its reach into the side of the palace, and a piece beside it on the inside cuts its reach to the front-centre point. Advisors and Elephants cannot stand on either leg point, so this job falls to Chariots, Horses and Cannons.

The other defence is to keep the General off the front corner. A General that climbs there has left the shelter of its Advisors, and against a Horse on the tiger point that corner is a dead end. When the climb is forced, as in the example, the real damage was done a move earlier, when the palace centre was allowed to fall under a Chariot's control.

For the attacker, the usual mistake is playing the Horse to the tiger point without checking the leg beside it. A Red piece standing there, for example a Soldier that has advanced to the soldier rank, quietly cancels the Horse's control of the front-centre point. The other is forgetting the back door: if the back corner behind the General is empty, the Horse check can be met by retreating into it.

Spotting the tiger point

Set up the two positions, play them as Red, then swap sides and look for a defence that isn't there. When the shape feels familiar, XiangqiPlay's 5,000 engine-proven mate puzzles, and games against the computer from Easy up to God with a free account, will give you plenty of chances to find the tiger point under pressure.