Brinkmate

Brinkmate is the situation in which an unavoidable checkmate sequence will be created by the player's next move.

In shogi, brinkmate is known as hisshi (必至 "desperation, inevitability" or 必死 "sure kill").

Note that in shogi tsume is defined as strictly forced mate sequences with constant checks.

Brinkmate differs from the situation in which a checkmate sequence is only being threatened to be created in the next move but is still avoidable if the opponent defends correctly.

This situation is known as threatmate or, in Japanese, 詰めろ tsumero ("threatened mate").

The only way to prevent a loss from a brinkmate is for the defender to not give their opponent a chance to actually create the checkmate sequence and instead initiate their own mating sequence (with constant checks) before their opponent's move.

Some brinkmates involve tsumes that needs two condition to be met in order to defend (e.g. two mates are threatened).

However, Black can create hisshi by moving and promoting their silver to the 74 square, that is 1.

From this position, Black is threatening to drop their gold in hand to 83 in their next move to render an immediate mate.

Figure 9 displays a hisshi problem based on a real shogi game.

But Black can create hisshi by preventing the king from going that way by dropping their silver to the 52 square, that is 1.

Any defense attempt by White (fleeing or dropping a defending piece) will fail.

Silver on the belly (腹銀 haragin "belly-silver") is a basic brinkmate tactic in shogi.

This tactic positions a silver (by moving there or by dropping) directly on either side of the opponent's king.

In example 1, there is no way to directly stop the mate, the 61, 62, 81 and 82 squares all needs to be protected, which could only be done by a dragon or horse.

But white doesn't have a dragon or horse on the board, but he can make one by checking on the first move by dropping his bishop on 27.

After Black moves his silver to block the check, the bishop can promote to 72 and defend.

Brinkmates (hisshi) and threatmates (tsumero) are also found in western chess.