Brinkmate Contents Shogi Western chess See also References Bibliography External links Navigation...
Shogi theoryChess theory
shogicheckmatewestern chess§Western chesstactic
In shogi, brinkmate or hisshi (必至 "desperation, inevitability" or 必死 "sure kill") is the situation in which an unavoidable 詰め tsume checkmate sequence will be created by the player's next move. (Note that in shogi tsume is defined as strictly forced mate sequences with constant checks.)
Hisshi 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 詰めろ tsumero ("threatened mate"). Thus, hisshi is an indefensible tsumero.
The only way to prevent a loss from a brinkmate is for a player to not give their opponent a chance to actually create the tsume checkmate sequence and instead initiate their own tsume (with constant checks) before their opponent's move. (Thus, a good exemplification of the saying the best defense is a good offense.)
Although the terms brinkmate and threatmate were coined to translate the Japanese terms, the concepts can equally be applied to western chess and other chess-like games. (See: §Western chess below.)
Contents
1 Shogi
1.1 Example
1.2 Hisshi vs tsumero
1.3 Silver on the belly tactic
2 Western chess
3 See also
4 References
5 Bibliography
6 External links
Shogi
Example
Fig. 1. (pre-)Hisshi problem ☖ pieces in hand: all the rest
☗ pieces in hand: 金 | Fig. 2. Hisshi (answer) ☖ pieces in hand: all the rest
☗ pieces in hand: 金 1. S-74+ |
Figure 1 shows a classic hisshi problem.[1] Here, Black does not have a way to immediately checkmate White's king or to immediately create a tsume forced mating sequence. However, Black can create hisshi by moving and promoting their silver to the 74 square, that is 1. S-74+ (Fig. 2).
Fig. 3. White's Response #1: Capture ☖ pieces in hand: all the rest
☗ pieces in hand: 金 1...Px74 | Fig. 4. Tsume #1 (1 move) ☖ pieces in hand: all the rest
☗ pieces in hand: – 2. G*83 |
From this position, Black is threatening to drop their gold in hand to 83 in their next move to render an immediate mate.
Even if White were to try to remove Black's promoted silver with ...Px74 (Fig. 3), this does nothing to prevent the simple mate in one with G*83 (Fig. 4).
Fig. 5. White's Response #2: Defend ☖ pieces in hand: all the rest
☗ pieces in hand: 金 1...G*82 | Fig. 6. Tsume #2 (3 moves) ☖ pieces in hand: all the rest
☗ pieces in hand: – 2. G*83 |
White has two possible ways to attempt to defend against this threat.
But, since this is hisshi and not merely tsumero, all attempts are futile as explained below.
If White tries to defend the 83 square by dropping a defender (such as a gold) to 82 (Fig. 5), then Black can initiate a 3-move forced mating sequence starting from 2. G*83 (Fig. 6).
Subsequent moves are 2...Gx83, 3. +Sx83 (tsumi).
Fig. 7. White's Response #3: Escape ☖ pieces in hand: all the rest
☗ pieces in hand: 金 1...K-82 | Fig. 8. Tsume #3 (3 moves) ☖ pieces in hand: all the rest
☗ pieces in hand: 金 2. +S-83 |
If White's king tries to flee to the 82 square (Fig. 7), then Black can initiate a 3-move mating sequence starting from 2. +S-83 (Fig. 8).
Subsequent moves are 2...K-71, 3. G*72 (tsumi).
Alternately, instead of 2. +S-83, Black could move P-83+ for another 3-move forced mating sequence, then 2...K-71, 3. G*72 (tsumi).
Hisshi vs tsumero
Tsumero only (not hisshi) ☖ pieces in hand: 金
☗ pieces in hand: 金 White to play | Hisshi (and tsumero) ☖ pieces in hand: 金
☗ pieces in hand: 金 White to play |
The first adjacent diagram has an example of tsumero that is not hisshi. It is now White's turn to play. Although Black has a possible checkmate in their next move by dropping their gold to the 82 square, White can defend against this by dropping a gold to 71 defending the 82 square. With this move, White has removed the threat of Black's tsumero. If Black dropped their gold to 82 now, then White would simply capture it and attack Black's other gold (that is, 1...G*71, 2. G*82 Gx82).
In the second diagram, there is an additional pawn positioned on the 73 square. This difference gives Black hisshi (as well as tsumero). Any defense attempt by White (fleeing or dropping a defending piece) will fail. White's 1...G*71 will be met with 2. G*72 Gx72, 3. Px72+ (tsumi). There are similar mate sequences if White tries 1...R*32, 1...G*82, etc. Similarly, it is impossible for White's king to escape with 1...K-71.
Silver on the belly tactic
Hisshi ☖ pieces in hand: all the rest
☗ pieces in hand: –
| Mate Sequence ☖ pieces in hand: all the rest
☗ pieces in hand: –
|
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. The adjacent diagram shows a typical silver on the belly brinkmate. Here the silver is placed on the 82 square. The one-move mates 2. +R-81, 2. +Rx91, 2. S-81=, or 2. Sx91+ are unstoppable. For instance, if White moves 1...P-94, then 2. +Rx91 is mate, and if White moves 1...N*81, then the silver or dragon taking 81 are mates.
That leaves the longest (7-move) mate sequence in which the king attempts a futile escape starting with 1...P-84. Subsequently, the dragon chases. Thus, 2. +Rx91 K-83, 3. +Rx93 K-72, 4. +R-73 K-61, 5. +R-71 is a mate.
Western chess
Brinkmates (hisshi) and threatmates (tsumero) are also found in western chess.
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See also
- Tsume shogi
- Checkmate
References
^ Fairbairn 1986, p. 29–30.
Bibliography
Fairbairn, John (1986). Shogi for beginners (2nd ed.). Ishi Press. ISBN 978-4-8718-720-10..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output .citation q{quotes:"""""""'""'"}.mw-parser-output .citation .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-maint{display:none;color:#33aa33;margin-left:0.3em}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
Kitao, Madoka (2014). Ending attack at a glance. Translated by Kawasaki, Tomohide. Nekomado. ISBN 978-4-9052-2513-3.
External links
- Shogi Shack:
- ABC of Hisshi
Simple Hisshi · 1-move and 3-move hisshi problems
- HIDETCHI's YouTube video: How to play Shogi (将棋): Lesson #31: Threatmate and Brinkmate
- Shogi Planet: How To Lead To Fundamental Brinkmate (必至)
