Riichi: Difference between revisions

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== Strategy ==
== Strategy ==
Calling riichi is an optional play.  Therefore, players often have to make various considerations, when it comes to using riichi.  Often, this depends on the discarded tiles, how early or late in the hand, the hand value, and/or the player's hand composition.  If possible, a player may opt not to use riichi at all and instead employ the strategy of [[damaten]].


=== Advantages ===
=== Advantages ===


Any closed hand becomes eligible for winning by ron.
* Any closed hand becomes eligible for winning by ron.
 
* Riichi is an automatic yaku and is eligible to count for 1 additional han (after a win).
Kans formed by any player provide two extra dora indicators for the riichi declarer instead of one.
* Kans formed by any player provide two extra dora indicators for the riichi declarer instead of one.
* Access to the [[dora|ura-dora]] (after a win).
* Other players are recommended to defend against riichi calls, if possible or needed.  Otherwise, players run the risk of falling to that hand.


=== Disadvantages ===
=== Disadvantages ===


It is less likely for opponents to deal in. In addition, it is impossible to change the composition of the hand in order to get a better wait or an improved score.
* It is less likely for opponents to deal in.
* By rule, the hand is locked.  Therefore, it is impossible to change the composition of the hand in order to get a better wait or an improved score.
* Likewise, a player can no longer defend and instead wait for a winning tile.
* Other players still have the option to develop their hands and potentially "snipe" the hand.  [http://tenhou.net/0/?log=2012111209gm-0009-7447-x33034e7e5279&tw=2&ts=4 Example].
* It is highly recommended to declare the win on the first instance of a winning tile.  Otherwise, the hand is subject to [[furiten]].  A riichi call disables a person's ability to be [[targeting|selective]] of points from particular players (if need be).


== Oikake riichi ==
== Oikake riichi ==

Revision as of 20:50, 9 October 2013

Riichi
Type Yaku
Kanji 立直 or リーチ
English Ready hand
Value 1 han (closed only)
Speed Varies
Difficulty At discretion

Riichi (立直 or リーチ) is the most commonly used yaku in the game. This yaku may apply to any closed hand and may be declared upon achieving tenpai. Due to its common usage, various specific game scenarios must be considered when using riichi.

Rules

When a player has a closed tenpai hand, the player may declare riichi. Doing so gains the hand 1 han. To declare riichi, a player announces riichi and discards a tile facing sideways in the discard pile. This is done to indicate when riichi was called. If that tile is claimed by another player for an open meld, then the next discard is turned sideways as a replacement.

Unless the first sideways discard is claimed for a win immediately, the riichi announcer now places a bet of 1,000 points on the table. This bet is collected by the next player to win a hand. Specific rulesets may handle differently what happens to the bet on a multiple win.

After a riichi declaration, the hand remains locked and unchangeable. In this state, the player is simply waiting for a winning tile to appear, either by draw or discard.

It is not allowed to declare riichi when less than four tiles remain in the wall. The player must be able to draw one more tile in an uninterrupted set of turns.

Ippatsu

Ippatsu (一発) is awarded if the player receives a winning tile within an uninterrupted set of turns after the riichi declaration. Tile calls interrupt the set of turns. The latest possible chance to win with ippatsu is with the player's next drawn tile after the riichi declaration. Ippatsu is a yaku worth 1 han.

Double riichi

Double riichi (ダブルリーチ) is a special case for riichi, where the player declares riichi on the first turn. No tile call may have interrupted the turn order before the declaration, where applicable. Double riichi is worth 2 han instead of 1 han, as a bonus for the initial timing.

Kan during riichi

When a riichi declarer holds three identical tiles and draws the fourth after the riichi announcement, he may form an ankan from these tiles instead of discarding the fourth. The hand composition and the possible winning tiles may not change: It is not allowed to declare kan if, for some possible winning tile, any of the three identical tiles may be interpreted as part of a shuntsu or part of the pair.

Illegal example:

, draw: .

It is not allowed to kan the fours. The manzu tiles may either be interpreted as a 3-4 ryanmen wait and a 4-4 pair, or as a 4-man ankou with a 3-man tanki wait. For a legal kan declaration, the three identical tiles would have to be an ankou in any interpretation. Had the player drawn a west wind, he would have been allowed to kan it.

Legal example:

, draw: , , or .

Furiten

If a riichi declarer does not win at first opportunity, he will be permanently furiten.

Ura dora

When a riichi declarer wins, he may flip the tiles underneath the dora and kan dora indicators. These flipped ura dora indicators may increase the value of his hand.

Tochuu ryuukoku

Tochuu ryuukoku, or abortive draw, is in effect when suucha riichi occurs. In this case, three riichis have been called; and a fourth one is called in place. If the discarded tile is not claimed for a win, then the hand ends.

Strategy

Calling riichi is an optional play. Therefore, players often have to make various considerations, when it comes to using riichi. Often, this depends on the discarded tiles, how early or late in the hand, the hand value, and/or the player's hand composition. If possible, a player may opt not to use riichi at all and instead employ the strategy of damaten.

Advantages

  • Any closed hand becomes eligible for winning by ron.
  • Riichi is an automatic yaku and is eligible to count for 1 additional han (after a win).
  • Kans formed by any player provide two extra dora indicators for the riichi declarer instead of one.
  • Access to the ura-dora (after a win).
  • Other players are recommended to defend against riichi calls, if possible or needed. Otherwise, players run the risk of falling to that hand.

Disadvantages

  • It is less likely for opponents to deal in.
  • By rule, the hand is locked. Therefore, it is impossible to change the composition of the hand in order to get a better wait or an improved score.
  • Likewise, a player can no longer defend and instead wait for a winning tile.
  • Other players still have the option to develop their hands and potentially "snipe" the hand. Example.
  • It is highly recommended to declare the win on the first instance of a winning tile. Otherwise, the hand is subject to furiten. A riichi call disables a person's ability to be selective of points from particular players (if need be).

Oikake riichi

Oikake riichi (追いかけリーチ) is a declared riichi, after another player had already declared riichi. In this state, two or even three players have simultaneously declared riichi; and thus, the game becomes a contest between two or three tenpai hands.

The process of four active riichi hands is not possible due to suucha riichi, or four called riichi. In this case, the hand ends if the fourth riichi discard is not a winning tile for any of the previous three.

External links

Riichi in Japanese Wikipedia
Ippatsu in Japanese Wikipedia.
Double riichi in Japanese Wikipedia.