Riichi strategy: Difference between revisions

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*If an opponent at iishanten decides to fold, great - one less hand to worry about.
*If an opponent at iishanten decides to fold, great - one less hand to worry about.


Due to this advantage, a player who declares riichi first exerts pressure on the other players. Other players may choose to give up their hands. Of course, this is not guaranteed, especially if the point standings force some other players to take on offense at all costs. However, you'll still have the advantage of being first tenpai, as mentioned above.
Due to these advantagse, a player who declares riichi first will exert pressure on the other players. Other players may choose to give up their hands. Of course, this is not guaranteed, especially if the point standings force some other players to take on offense at all costs. However, you'll still have the advantages listed above.


Conversely, a chasing riichi (riichi after another player has declared riichi) is weaker, due to the reasons mentioned above.
Conversely, a chasing riichi (riichi after another player has declared riichi) is weaker, for the same reasons.
 
=== Hand shape and waits ===
 
Once a hand reaches tenpai, the chance of winning largely depends on the [[machi|tile waits]]. Hands that waits of three tiles or greater, such as [[ryanmenten]] or [[sanmentan]], have a favorable chance of winning, while one tile waits like [[kanchan]] or [[tanki]] are less likely to win.
 
Since most of the risks of riichi only apply if the hand fails to win, having a good wait means that riichi is more desirable. Bad shape waits may be more pressured to keep the possibility of failure in mind, as well as the possibility of changing the hand into having a better wait.


=== Score ===
=== Score ===
Riichi gives 1 han, and possibly more via ippatsu and ura dora. Since every han doubles your score until you reach [[mangan]], so these are all valuable. However, there are rare cases where score does not matter.
Riichi gives 1 han, and possibly more via ippatsu and ura dora. Since every han doubles your score until you reach [[mangan]], these are all valuable. However, there are rare cases where score does not matter.


*When riichi wouldn't actually change your points. For example, [[haneman]] is scored with 6 or 7 han. If you have a 6 han hand, riichi's +1 han would still result in a haneman. Getting [[mentsumo]], ippatsu, and/or ura dora will increase it up to baiman, but these are unreliable.
*When riichi wouldn't actually change your hand value. For example, [[haneman]] is scored with 6 or 7 han. If you have a 6 han hand, riichi's +1 han would still result in a haneman. Getting [[mentsumo]], ippatsu, and/or ura dora will increase it up to baiman, but these are unreliable.
*When you are in first with a large lead. In this case, you may damaten to increase hand win rate, allowing you to end the game faster.
*When you are in first with a large lead. In this case, you may damaten to increase hand win rate, allowing you to end the game faster.
*When you have a valuable hand. If you have a guaranteed mangan or higher hand, the extra score may not be worth the loss of win rate.
*When you have a valuable hand. If you have a guaranteed mangan or higher hand, the extra score may not be worth the loss of win rate.


That being said, the extra points from riichi often do matter. It's a game about scoring the most points, after all.
That being said, the extra points from riichi often do matter. It's a game about scoring the most points, after all.
=== Furiten ===
{{main|Furiten}}
Declaring riichi means that, if the player declines the first possible ron, then they enter permanent [[furiten]]. A damaten hand only enters furiten until the dama player's next discard.
First, damaten has better control over [[yasume]]. If a riichi hand wins off a bad wait, you have to accept it or enter furiten. However, since riichi adds an average of around 1.5 han, this is only an issue if the waits differ by 3+ han. Even then, you may want to riichi despite that.
Second, a damaten hand can try and target a specific player. This can be done to [[gyakuten|change placement]] (e.g. targeting 1st place as 2nd). However, since riichi gives a hefty point bonus, you may change placement even if you ron the "wrong" player.
Alternatively, you may want to ron to get a player below 0 points, ending the round immediately. Or you may wish to avoid calling ron on a player with 0 points, to not end the round.
=== Game round ===
{{main|Kyoku}}
Generally, in the first half of the entire game, a player's exact placement is not as large of a concern. There are many opportunities to make up differences: a player who's ahead can hardly afford to rest on their laurels, while players who are behind are not as desperate. Thus, situations tend to be more "general" - riichi's increased reward is usually appreciated, its intimidation effect more often felt, and it is more often a good idea. In other words, in the earlier half, going for sheer points is often more important than going for placement.
When the game is closer to its end (generally around the second half, but may be earlier if particularly large wins and losses have been going on), point standing becomes more of a concern. If the game could end on the next round, gaining +1000 points to go from 3rd to 2nd becomes much more valuable. At this stage, players who are ahead may not want to riichi, as the risks are amplified, among other considerations.


=== Hand lock ===
=== Hand lock ===
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Also, the hand lock prevents you from defending. Often, the reward is worth the risk. But if the risk of dealing in is greater than the reward of winning the hand with additional value, then it can be a bigger point of consideration.
Also, the hand lock prevents you from defending. Often, the reward is worth the risk. But if the risk of dealing in is greater than the reward of winning the hand with additional value, then it can be a bigger point of consideration.


=== Hand shape and waits ===
=== Furiten ===
{{main|Furiten}}
 
Declaring riichi means that, if the player declines the first possible ron, then they enter permanent [[furiten]]. A damaten hand only enters furiten until the dama player's next discard.
 
First, damaten has better control over [[yasume]]. If a riichi hand wins off a bad wait, you have to accept it or enter furiten. However, since riichi adds an average of around 1.5 han, this is only an issue if the waits differ by 3+ han. Even then, you may want to riichi despite this.
 
Second, a damaten hand can try and target a specific player. This can be done to [[gyakuten|change placement]] (e.g. targeting 1st place as 2nd). However, since riichi gives a hefty point bonus, it might change placement even if you ron the "wrong" player. Alternatively, you may want to ron to get a player below 0 points, ending the round immediately. Or you may wish to avoid calling ron on a player with 0 points, to not end the round.
 
=== Game round ===
{{main|Kyoku}}


Once a hand reaches tenpai, the chance of winning largely depends on the [[machi|tile waits]]. Hands that waits of three tiles or greater, such as [[ryanmenten]] or [[sanmentan]], have a favorable chance of winning, while one tile waits like [[kanchan]] or [[tanki]] are less likely to win.  
Generally, in the first half of the entire game, a player's exact placement is not as large of a concern. There are many opportunities to make up differences: a player who's ahead can hardly afford to rest on their laurels, while players who are behind are not as desperate. Thus, situations tend to be more "general" - riichi's increased reward is usually appreciated, its intimidation effect more often felt, and it is more often a good idea. In other words, in the earlier half, going for sheer points is often more important than going for placement.


Since most of the risks of riichi only apply if the hand fails to win, having a good wait means that riichi is more desirable. Bad shape waits may be more pressured to keep the possibility of failure in mind, as well as the possibility of changing the hand into having a better wait.
When the game is closer to its end (generally around the second half, but may be earlier if particularly large wins and losses have been going on), point standing becomes more of a concern. If the game could end on the next round, gaining +1000 points to go from 3rd to 2nd becomes much more valuable. At this stage, players who are ahead may not want to riichi, as the risks are amplified, among other considerations.


=== Point standing ===
=== Point standing ===
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When the game is closer to its end, point standing can affect the decision to declare riichi or not.
When the game is closer to its end, point standing can affect the decision to declare riichi or not.
*Players that are ahead will be more cautious. Late in the game, increasing their lead will not matter as much, while the risk of deal-in matters more. Meanwhile, players who are behind will want to riichi to catch up. Players in the middle should analyze their own specific situations to determine if riichi is right.
*Players that are ahead will be more cautious. Late in the game, increasing their lead will not matter as much, while the risk of deal-in matters more. Meanwhile, players who are behind will want to riichi to catch up. Players in the middle should analyze their own specific situations to determine if riichi is right.
*The 1000 points used to declare riichi could cause you to drop down placement. If this is the case during all last or South 3, you probably shouldn't riichi if you have other yaku.
*The 1000 points used to declare riichi could cause you to drop down placement. If this is the case during all last or possibly South 3, you probably shouldn't riichi, especially if you have another yaku.
*If a damaten win and riichi win would cause you to end up in the same rank, you should dama.
*If a damaten win and riichi win would cause you to end up in the same rank, you should dama.


=== Winning chance ===
=== Winning chance ===


Pressing players to defend will lower your chance of winning. Assuming a dama hand would have yaku, declaring riichi will generally lower your winrate by about 40%. Therefore, if winning matters and the extra score does not matter you should dama.
Pressing players to defend will lower your chance of winning. Assuming a dama hand can ron, declaring riichi will generally lower your winrate by about 40%. Therefore, if winning matters and the extra score does not matter you should dama. Also, with valuable hands (mangan/haneman or above), dama is usually better.


A hand which has an extremely poor wait (e.g single tile wait on dora, or a [[hell wait]]) are so bad that riichi doesn't reduce their chance of winning by much.
A hand which has an extremely poor wait (e.g single tile wait on dora, or a [[hell wait]]) are so bad that riichi doesn't reduce their chance of winning by much.
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