Riichi strategy: Difference between revisions

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[[Image:Bad_riichi.png|right|250px|thumb|An ill-advised and unnecessary [http://tenhou.net/0/?log=2014092217gm-0089-0000-3fd71626&tw=3&ts=8 riichi].]]
[[Image:Bad_riichi.png|right|250px|thumb|An ill-advised and unnecessary [http://tenhou.net/0/?log=2014092217gm-0089-0000-3fd71626&tw=3&ts=8 riichi].]]
Strategy surrounding the call for [[riichi]] entails various considerations.  While declaring riichi gives players the chance for [[Scoring|higher scoring]] hands, players must not be blinded by the opportunity without considering the risks. Sometimes, the riichi may do nothing but harm you. Regardless, it's best not to blindly call riichi every time you reach tenpai.
Strategy surrounding the call for [[riichi]] entails various considerations.  While declaring riichi gives players the chance for [[Scoring|higher scoring]] hands, players must not be blinded by the opportunity without considering the risks. Sometimes, the riichi may be a good idea, or it may do nothing but harm you. Regardless, it's best not to blindly call riichi every time you reach tenpai.


==Assessing riichi==
==Assessing riichi==
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There is an advantage to being the first to tenpai, and thus an advantage to being the first to declare riichi. Only one hand can win per round, so faster hands could just win before anyone else. A tenpai hand can call ron, which is superior to the calls of [[chii]] and [[pon]]. Also, the earlier you declare riichi, the less safe tiles are available. A riichi in the 6th round is much harder to defend from than a riichi in the 16th round.
There is an advantage to being the first to tenpai, and thus an advantage to being the first to declare riichi. Only one hand can win per round, so faster hands could just win before anyone else. A tenpai hand can call ron, which is superior to the calls of [[chii]] and [[pon]]. Also, the earlier you declare riichi, the less safe tiles are available. A riichi in the 6th round is much harder to defend from than a riichi in the 16th round.


In addition, opponents who are not in tenpai may need to discard dangerous tiles to reach tenpai. Advancing from [[iishanten]] to tenpai can take a while; even with great [[ukeire|tile acceptance]], it'll often take multiple turns to do so. (This, of course, depends on luck.)
In addition, going from [[iishanten]] to tenpai can take a while. Even with great [[ukeire|tile acceptance]], it'll often take multiple turns to do so. (This, of course, depends on luck.) In order to reach tenpai in the first place, an opponent may need to discard multiple dangerous tiles.
*If an opponent at iishanten decides to attack into your riichi, they might need to discard unsafe tiles for multiple turns. Therefore, you'll get multiple chances to win off ron.
*If an opponent at iishanten decides to attack into your riichi, they could have to discard unsafe tiles for multiple turns. Therefore, you'll get multiple chances to win off ron.
*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 these advantages, 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.
Due to these advantages, a player who declares riichi first will often 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, for the same reasons.
Conversely, a chasing riichi (riichi after another player has declared riichi) is weaker, for the same reasons.
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*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 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 without needing riichi, 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.
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{{main|Kyoku}}
{{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 can be more important than going for placement.
Generally, in the first half of the entire game, a player's precise ranking 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 can be more important than going for rank.


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.
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.
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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 dealing 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 dealing 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 possibly South 3), you probably shouldn't riichi, especially if you have another yaku.
*The 1000 points used to declare riichi could cause you to drop down placement. If this is the case during all last, you probably shouldn't riichi 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 has yaku (i.e. 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.
Pressing players to defend will lower your chance of winning. Assuming a dama hand has a yaku (i.e. it 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) 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) are so bad that riichi doesn't reduce their chance of winning by much.
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== Oikake riichi ==
== Oikake riichi ==


'''Oikake riichi''' {{kana|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.  In this state, any riichi declarer is liable of playing into another's riichi call.  At the time same, this type of riichi is often utilized because at least one player is not able to defend.  With multiple riichis occurring simultaneously, the players end up in a "riichi duel".
'''Oikake riichi''' {{kana|追いかけリーチ}} is a "chasing riichi", or 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.  In this state, any riichi declarer is liable of playing into another's riichi call.  At the time same, this type of riichi is often utilized because at least one player is not able to defend in the first place.  With multiple riichis occurring simultaneously, the players end up in a "riichi duel".


The process of four active riichi hands is not possible due to [[Tochuu ryuukyoku|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.
The process of four active riichi hands is not possible due to [[Tochuu ryuukyoku|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.
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