Furiten: Difference between revisions

From Japanese Mahjong Wiki
Jump to navigation Jump to search
(name the header "discard furiten" instead of "common case", since discard furiten is the class of furiten being talked about)
(improve wording overall. try to fix some subjective parts of "discard furiten" section)
Line 1: Line 1:
[[Image:Furiten.png|right|thumb|250px|[http://tenhou.net/0/?log=2012110112gm-0009-7447-14ec5c8d&tw=0&ts=4 Baiman tenpai], in furiten due to 9-sou in discard.  Ron cannot be called here.]]
[[Image:Furiten.png|right|thumb|250px|[http://tenhou.net/0/?log=2012110112gm-0009-7447-14ec5c8d&tw=0&ts=4 Baiman tenpai], in furiten due to 9-sou in discard.  Ron cannot be called here.]]
'''Furiten''' {{kana|振聴}} is a restriction applied to [[tenpai]] hands. While in furiten, the player loses the ability to declare a win on any player's [[ron|discard]] (ron). The most common form of furiten is with discards: if any tile the hand could have won off is in a player's discard pile, it is furiten. This includes any tiles [[naki|called by opponents]]. Other cases involving riichi and temporary furiten are also applicable.  Regardless, the hand can still win by [[tsumo|self-draw]] (tsumo) given valid [[yaku]].
While a player's hand is in '''furiten''' {{kana|振聴}}, the player cannot declare a win on another player's [[ron|discard]] (i.e., they cannot [[ron]]). They are still allowed to win with their own draw ([[tsumo]]), assuming the hand is valid.


This rule is often used for [[defense]] purposes to determine [[Genbutsu|safe tiles]]. Tiles with the furiten rule can be inferred via [[suji]], though this may not be guaranteed.
The most common form of furiten is with discards: if any tile a player's hand could have won off had been discarded before, it is furiten. A hand may also enter furiten when a player skips a win.  


== Rule statement ==
This rule is often used for [[defense]] purposes to determine [[genbutsu|safe tiles]]: any tile a player discards is 100% safe against that player.
A hand in tenpai is in furiten in any of the following scenarios:


* At least one winning tile is in one's own discard pile. This applies even if the hand could not actually win off that tile (due to lacking yaku).
== Rule overview ==
* The hand is declared [[riichi]] and the (first) winning tile is not claimed. This is known as permanent furiten.
A hand in [[tenpai]] is in furiten in any of the following scenarios:
* The hand is not declared riichi, another player discards a tile, and the winning tile is not claimed, even if the hand could not actually win. Then the hand is in temporary furiten and cannot ron until the player has discarded.


While in furiten, the hand is unable to call ron upon a discard. However, it is still winnable via self-draw, assuming the hand has valid yaku. Note: when any winning tile triggers furiten, the ''entire'' hand is furiten.
* '''Discard furiten:''' When at least one winning tile had been discarded before, the hand enters furiten. This applies even if the hand couldn't actually win if it got that tile (due to lacking [[yaku]]). A  does not have to be in your discard pile to invoke furiten; if an opponent [[naki|called]] a tile, it will still trigger fuirten.
* '''Permanent furiten:''' After declaring [[riichi]], if the first winning tile is skipped, the hand permanently enters furiten. 
* '''Temporary furiten:''' When not in riichi, when a winning tile is skipped, the hand enters temporary furiten. This furiten lasts until the player's next draw.
 
While in furiten, the hand is unable to call ron upon a discard. However, it is still winnable via self-draw, assuming the hand has valid yaku.
 
Note: If a hand is in furiten, it is unable to win off ''any'' player's discard, regardless of which tile caused the furiten. For example, if your hand is waiting to win with 2p and 5p, and you had discarded 2p before, you are unable to win off an opponent's 5p.


=== Discard furiten ===
=== Discard furiten ===
Line 24: Line 28:
}}
}}


The most common case of furiten involves a player's own discard. If a winning tile is in a player's discard, then the hand is in furiten.
The most common case of furiten involves a player's own discard. If a player's own winning tile had been discarded before, then their hand enters furiten.


All of a player's discards can be checked at any time during play, by looking at their discard pools and the rotated tiles in other players' tile calls. This leads to the most basic strategy to avoid dealing into a player's hand: tiles they have already discarded are guaranteed to be safe against a ron call from that player.
You can tell what tiles a player discarded by looking at their discard pile, and looking at the rotated tiles in other players' tile calls. This leads to the most basic strategy to avoid dealing into a player's hand: tiles they have already discarded are guaranteed to be safe against a ron call from that player.


During hand development, it is important to bear furiten in mind. Most of the time, if a hand gets to tenpai and is furiten at that point, it indicates that the hand was inefficiently developed. This is not always the case, as sometimes a player makes a tactically correct decision and finds themselves in furiten anyway.
It is important to bear furiten in mind when developing a hand. Frequently, if a hand gets to tenpai and is furiten, then the hand was inefficiently developed. This is not always the case, however, as a player can make a correct decision but still be in furiten.


The most common reason for furiten, however, is when a player is already tenpai with an open hand, and does not have a guaranteed yaku. While they may have a winning tile that provides them with a yaku, if they draw another tile which completes the hand without a yaku, then they will be forced into furiten on the next discard. This most commonly occurs when the hand has:
A common reason for furiten is when a player is in tenpai with an open hand, but it has no guaranteed yaku. In these scenarios, a hand only gains yaku if it draws a certain winning tile. If a different winning tile is drawn, the hand will have no yaku, and is thus forced to discard its own winning tile - entering furiten. This most commonly occurs with:
*A [[shanpon]] wait, with one tile completing a [[yakuhai]] triplet, and the other having no yaku.
*A [[shanpon]] wait, with one tile completing a [[yakuhai]] triplet, and the other having no yaku.
*A [[ryanmen]] wait on 14 or 69 on a hand that would otherwise complete [[tanyao]].
*A [[ryanmen]] wait on 14 or 69 on a hand that would otherwise complete [[tanyao]].
Line 36: Line 40:


Finally, a player considering a [[daburu riichi|double riichi]] should carefully inspect their hand before discarding; if they had a complete hand to begin with, then being in furiten will add insult to the injury of having [[http://osamuko.com/delicious-riichi-button-must-click-it/ passed]] on a [[tenhou and chiihou|tenhou or chiihou tsumo]].
Finally, a player considering a [[daburu riichi|double riichi]] should carefully inspect their hand before discarding; if they had a complete hand to begin with, then being in furiten will add insult to the injury of having [[http://osamuko.com/delicious-riichi-button-must-click-it/ passed]] on a [[tenhou and chiihou|tenhou or chiihou tsumo]].
A hand can escape this type of furiten by changing its waits.


'''Example tenpai hand'''
'''Example tenpai hand'''
Line 47: Line 53:
=== Temporary furiten ===
=== Temporary furiten ===
[[Image:TempFuriten.png|thumb|right|250px|Ron declined, so [http://tenhou.net/0/?log=2014022617gm-0089-0000-ee8c6631&tw=2&ts=11 temporary furiten invoked] until the next own's tile draw.]]
[[Image:TempFuriten.png|thumb|right|250px|Ron declined, so [http://tenhou.net/0/?log=2014022617gm-0089-0000-ee8c6631&tw=2&ts=11 temporary furiten invoked] until the next own's tile draw.]]
Any player in tenpai has the option to ignore a winning tile. By declining a call for ron, the player then becomes temporarily furiten until their next discard. This is called '''temporary furiten''', as it expires shortly after it occurs. This applies to a discarded tile, as well as tiles used to create a [[shouminkan]]. [[Ankan]] are exempt: the only hand that can ron of an ankan is a single-sided [[kokushi musou]], and if ron happens to be skipped, the hand becomes impossible.
Any player in tenpai has the option to ignore a winning tile. By declining a call for ron, the player then becomes temporarily furiten until their next discard. This is called '''temporary furiten''', because it only lasts for 1 turn. This applies to discarded tiles, as well as tiles used to create a [[shouminkan]].


The primary purpose of the rule is to prevent a player from targeting a later player in the turn order. Once a player sees a tile discarded, they know that they can follow with the same tile and it will be safe for that turn.
The primary purpose of the rule is to prevent a player from targeting a later player in the turn order. Once a player sees a tile discarded, they know that they can follow with the same tile and it will be safe for that turn.


While this is often a mistake to enter temporary furiten, done by a player who does not know their waits correctly or is not paying attention, it may be done deliberately in order to achieve a higher scoring hand or to target a specific player. This becomes much more common in [[orasu]], where a player may gain little benefit from winning a hand that does not [[gyakuten|let them pass another player]]. Temporary furiten can also be entered by a player who does not have a guaranteed yaku, as described above. This is much less devastating than drawing the [[yasume]] tile, however, because it is only temporary.
A player may deliberately skip a win, entering temporary furiten in the process. This is often done after [[situational analysis|point standing analysis]]: for example, if a player is close to [[tobi|bankrupting]], a player in 1st may want to target them in order to end the game faster. When close to [[orasu|all last]], a player may need to ron a specific player to [[gyakuten|rise up in rank]]. Temporary furiten can also be entered by a player who does not have a guaranteed yaku, as described above. Otherwise, a player may mistakenly enter furiten if they don't know their waits correctly.


Uncommonly, some rulesets [[Rule variations#Furiten|vary the rules]] by allowing a tile call made by another player to cancel temporary furiten. This variation is considered by many to be a poor one.
Rarely, some rulesets [[Rule variations#Furiten|vary the rules]] by allowing a tile call made by another player to cancel temporary furiten.


=== Permanent furiten during riichi ===
=== Permanent furiten during riichi ===
Line 59: Line 65:
{{main|Riichi}}
{{main|Riichi}}


When a player has declared riichi, the state of temporary furiten does not expire. Per the rule of riichi, a player cannot change wait. Therefore, the hand can no longer be adjusted to escape furiten.  The only one opportunity to call ron comes from the first instance of a winning discarded tile.  If the call to win is declined, then the only option to win the hand comes via tsumo. This rule is a critical part of defense against riichi, as it means that any tiles discarded since the declaration is safe to the riichi called player.
When a player has declared riichi, the state of temporary furiten does not expire. Therefore, if a riichi hand skips a win, it is no longer able to call ron.


A player in riichi never has to worry about [[yasume]] putting them in furiten unless they are playing with [[ryanhan shibari]]. When ryanhan shibari, a riichi without a guaranteed second yaku may be quite dangerous due to furiten.
The purpose of this rule is to make it easier to defend against riichi. Any tiles discarded since the declaration is safe against that riichi player.
 
A player in riichi never has to worry about having no yaku unless they are playing with [[ryanhan shibari]]. When ryanhan shibari, a riichi without a guaranteed second yaku may be quite dangerous due to furiten.


== Strategy ==
== Strategy ==


=== Defense ===
=== Defense ===
{{main|Defense}}


{{main|Defense}}
The furiten rule is essential for defensive play. Any tile that would invoke furiten to a player is 100% safe against that player:
*Discard furiten: Any tile that an opponent discarded is 100% against them.
*Permanent furiten: an opponent declares [[riichi]], any tile anyone discards (and not won off of) is 100% safe against that riichi player.
*Temporary furiten: Any tile that the player to your left has discarded this turn is 100% safe against every player for this turn only.


The furiten rule may be applied for defensive play, which focuses on discarding [[safe tiles]]. By discarding tiles that are also visible in an opponent's discard pile, a player can avoid a ron call by that opponent.  Likewise, usage of [[suji]] and [[kabe]] may also help players deduce safe tiles, based on opponent discard.  This is applied when a player does not have any matching tiles in the hand with opponent discard; or a player may rather keep certain tiles, for the sake of developing the hand without [[betaori|tearing it apart]].
[[Suji]] is a technique that is related to furiten. When a tile is suji, a hand cannot have a [[ryanmen]] wait (2-sided wait; the most common type of wait) for that tile without being in furiten.


===Working with furiten===
===Working with furiten===


Sometimes, it may be necessary to deliberately place the hand in furiten. Often, this is the result of developing the hand and defending simultaneously.  To escape the bind applied by furiten, then the hand's [[machi|tile wait(s)]] must simply change by adjusting and changing the tiles in the hand with subsequent tile draws.  Of course, a player may place greater expectation on tsumo to win rather than ron.
Sometimes, it may be necessary to enter tenpai, even while in furiten. Often, this is the result of developing the hand and defending simultaneously.  
 
On rare occasions, a player may hold a tenpai hand with [[damaten]].  The hand may invoke [[riichi]], but the player had chosen not to for some reason.  Eventually, a winning tile may arrive; and instead of declaring a win, the player opts to call riichi.  That instantly puts the hand in furiten opting to win by tsumo later.


=== Furiten tsumo ===
To exit discard furiten, you can change the hand's [[wait]] so that it can no longer win off any of the discarded tiles. Alternatively, you can rely on tsumo rather than ron.


Hands in furiten can still win, as furiten imposes a limit of tsumo only. For open hands, the hand requires a valid yaku. For closed hands, [[mentsumo]] will be acceptable or added.
Rarely, a hand in [[damaten]] can intentionally enter furiten. In this case, the hand is in tenpai, but after a winning tile is drawn, the player does not declare a win but declares riichi - immediately entering furiten. This may be done to score [[pinfu]] + [[mentsumo]] in all last.


== External links ==
== External links ==

Revision as of 14:36, 26 June 2024

Baiman tenpai, in furiten due to 9-sou in discard. Ron cannot be called here.

While a player's hand is in furiten 「振聴」, the player cannot declare a win on another player's discard (i.e., they cannot ron). They are still allowed to win with their own draw (tsumo), assuming the hand is valid.

The most common form of furiten is with discards: if any tile a player's hand could have won off had been discarded before, it is furiten. A hand may also enter furiten when a player skips a win.

This rule is often used for defense purposes to determine safe tiles: any tile a player discards is 100% safe against that player.

Rule overview

A hand in tenpai is in furiten in any of the following scenarios:

  • Discard furiten: When at least one winning tile had been discarded before, the hand enters furiten. This applies even if the hand couldn't actually win if it got that tile (due to lacking yaku). A does not have to be in your discard pile to invoke furiten; if an opponent called a tile, it will still trigger fuirten.
  • Permanent furiten: After declaring riichi, if the first winning tile is skipped, the hand permanently enters furiten.
  • Temporary furiten: When not in riichi, when a winning tile is skipped, the hand enters temporary furiten. This furiten lasts until the player's next draw.

While in furiten, the hand is unable to call ron upon a discard. However, it is still winnable via self-draw, assuming the hand has valid yaku.

Note: If a hand is in furiten, it is unable to win off any player's discard, regardless of which tile caused the furiten. For example, if your hand is waiting to win with 2p and 5p, and you had discarded 2p before, you are unable to win off an opponent's 5p.

Discard furiten

Example discard pile



2-pin in this discard applies furiten to the example hand

The most common case of furiten involves a player's own discard. If a player's own winning tile had been discarded before, then their hand enters furiten.

You can tell what tiles a player discarded by looking at their discard pile, and looking at the rotated tiles in other players' tile calls. This leads to the most basic strategy to avoid dealing into a player's hand: tiles they have already discarded are guaranteed to be safe against a ron call from that player.

It is important to bear furiten in mind when developing a hand. Frequently, if a hand gets to tenpai and is furiten, then the hand was inefficiently developed. This is not always the case, however, as a player can make a correct decision but still be in furiten.

A common reason for furiten is when a player is in tenpai with an open hand, but it has no guaranteed yaku. In these scenarios, a hand only gains yaku if it draws a certain winning tile. If a different winning tile is drawn, the hand will have no yaku, and is thus forced to discard its own winning tile - entering furiten. This most commonly occurs with:

  • A shanpon wait, with one tile completing a yakuhai triplet, and the other having no yaku.
  • A ryanmen wait on 14 or 69 on a hand that would otherwise complete tanyao.

These type of cases are known as atozuke.

Finally, a player considering a double riichi should carefully inspect their hand before discarding; if they had a complete hand to begin with, then being in furiten will add insult to the injury of having [passed] on a tenhou or chiihou tsumo.

A hand can escape this type of furiten by changing its waits.

Example tenpai hand

Waiting for:

This hand waits on three different tiles. If the player has a 2-pin in their discard pile, then the hand is in furiten and may not win by ron on any tile. Even if a 5-pin or 8-pin gets discarded by an opponent, ron may not be called.

Temporary furiten

Ron declined, so temporary furiten invoked until the next own's tile draw.

Any player in tenpai has the option to ignore a winning tile. By declining a call for ron, the player then becomes temporarily furiten until their next discard. This is called temporary furiten, because it only lasts for 1 turn. This applies to discarded tiles, as well as tiles used to create a shouminkan.

The primary purpose of the rule is to prevent a player from targeting a later player in the turn order. Once a player sees a tile discarded, they know that they can follow with the same tile and it will be safe for that turn.

A player may deliberately skip a win, entering temporary furiten in the process. This is often done after point standing analysis: for example, if a player is close to bankrupting, a player in 1st may want to target them in order to end the game faster. When close to all last, a player may need to ron a specific player to rise up in rank. Temporary furiten can also be entered by a player who does not have a guaranteed yaku, as described above. Otherwise, a player may mistakenly enter furiten if they don't know their waits correctly.

Rarely, some rulesets vary the rules by allowing a tile call made by another player to cancel temporary furiten.

Permanent furiten during riichi

Furiten riichi applied upon declaration and discard declining a winning hand.

When a player has declared riichi, the state of temporary furiten does not expire. Therefore, if a riichi hand skips a win, it is no longer able to call ron.

The purpose of this rule is to make it easier to defend against riichi. Any tiles discarded since the declaration is safe against that riichi player.

A player in riichi never has to worry about having no yaku unless they are playing with ryanhan shibari. When ryanhan shibari, a riichi without a guaranteed second yaku may be quite dangerous due to furiten.

Strategy

Defense

The furiten rule is essential for defensive play. Any tile that would invoke furiten to a player is 100% safe against that player:

  • Discard furiten: Any tile that an opponent discarded is 100% against them.
  • Permanent furiten: an opponent declares riichi, any tile anyone discards (and not won off of) is 100% safe against that riichi player.
  • Temporary furiten: Any tile that the player to your left has discarded this turn is 100% safe against every player for this turn only.

Suji is a technique that is related to furiten. When a tile is suji, a hand cannot have a ryanmen wait (2-sided wait; the most common type of wait) for that tile without being in furiten.

Working with furiten

Sometimes, it may be necessary to enter tenpai, even while in furiten. Often, this is the result of developing the hand and defending simultaneously.

To exit discard furiten, you can change the hand's wait so that it can no longer win off any of the discarded tiles. Alternatively, you can rely on tsumo rather than ron.

Rarely, a hand in damaten can intentionally enter furiten. In this case, the hand is in tenpai, but after a winning tile is drawn, the player does not declare a win but declares riichi - immediately entering furiten. This may be done to score pinfu + mentsumo in all last.

External links

Furiten in Japanese Wikipedia