"Hand Must Be Concealed"

[cavemaneca]

There are some hands that need to be concealed for the yaku, like pinfu. Now, I keep getting mixed results reading things in different rule sets, so I just want it to be clear...
If you ron, does the hand still count as concealed?

Example from a website:
Four Closed Sets (Limit Hand)



Tsumo

In this case, the last tile must be taken off the wall (Tsumo) to complete Four Closed Sets. Taking the or off a player (Ron) would make the last Set outside, for All Sets (2) + 3-Closed Sets (2) + Red or White (1) = 5 Han.



From EMA Rules:
A concealed hand can be won on a discard. If the discarded winning tile finishes a pung, the pung is considered open when
scoring the minipoints, but the hand as such is still concealed.


So, at least according to EMA, wouldn't that still count as suu ankou?

[Rosti]

If you ron, providing your hand was concealed up until then, it is still considered concealed (ron would give you weakly closed, tsumo would give you strongly/fully closed, which is another yaku in itself). That is to say that yaku which must be concealed such as pinfu (pointless/all chi) and Ii Pei Kou (same chi twice) are still valid yaku if you win through ron, providing your entire hand is otherwise closed.

The ONLY exception to this is for the Suu An Kou (Four closed pon) yakuman hand, which appears to be what's confusing you. The case is that for you to get the yakuman (instead of just quite an awesome hand) then all four pons must be formed entirely within your closed hand, with you drawing every single tile for those pons yourself.
You can actually win with Suu An Kou and a ron, providing you've already formed the four closed pons in your hand, and you call ron to complete the pair with your final tile, which doesn't have anything to do with the four closed pons. So in your example, if the hand instead had three white dragons and just one red dragon, then you would be able to take the final red dragon with a ron call, and it would still be a yakuman.

I don't know if the EMA rules hold the exception for Suu An Kou, but my understanding of the standard riichi rulesets is that the exception exists.

I hope I've cleared up the confusion.

[Referee]

That is right, and the rules the OP quoted don't contradict each other. When you ron, the set you complete is considered open, even if the hand is still considered closed, therefore, you only have three closed pon, not four.

[cavemaneca]

thnx for the explanation. after reading it, EMA does explain the exception for suu ankou. no wonder i was confused... it was a sorta abstract reading of the rules..

That is right, and the rules the OP quoted don't contradict each other. When you ron, the set you complete is considered open, even if the hand is still considered closed, therefore, you only have three closed pon, not four.

This especially helped with getting why it's an exception...
so, as an example that would that not ruin Iipeikou if you steal for the second chow? but for san ankou that would ruin it if you had 1 chow and ron'd the last pung?

[Rosti]

Ii Pei Kou still counts if you ron to complete the second set.

Ii Pei Kou requires the hand to be closed. Sou An Kou and Suu An Kou required the pon to be closed.

You can get Sou An Kou (three closed pon) with a hand that is open. If you have three closed pon and, say, an open chi, then you'll still get the two yaku for Sou An Kou. Your hand is open, but the pon are closed, so it's valid.
With Ii Pei Kou, the whole hand has to be closed. It doesn't matter if you've got both chi closed, if any part of your hand is open then they no longer count.

Basically calling ron makes whatever meld you call on to be counted open, but it doesn't make your hand itself open.

[Referee]

Rosti: San Ankou. San Ankou is three closed pon. Suu Ankou is four closed pon.

To cavemaneca's questions: Yes, Iipeikou is still valid if you ron the second chi. San Ankou would be ruined if you had closed pon-pon-pair-pair and an open chi (or pon) and you ron, but again, it's valid if you had closed pon-pon-pon-single and ron the single for the pair.

[Rosti]

Rosti: San Ankou. San Ankou is three closed pon. Suu Ankou is four closed pon.

Ah, my bad. The webpage I was using as a reference has it listed with the incorrect name then.

I generally use the English names, so I'm not completely up to scratch on the Japanese ones. Plus it's hardly a common yaku

[cavemaneca]

thnx all now makes perfect sense!
btw, as far as the tenhou score quiz, is there any way to contact the creator? I'd like to ask if the java applet could be written to run as a jar, so i could use it on a smartphone, since apparently opera and whatnot don't run applets...

[Referee]

If you're going to try with tenhou's quiz, it has a bug that makes it count san ankou and suu ankou as valid even when ron would break them, which would have added to your confusion.

[chalwa]

to contact quiz creator you can ask at irc://irc.rizon.net/mahjong

[cavemaneca]

to contact quiz creator you can ask at irc://irc.rizon.net/mahjong

I was wondering about that. Site says "Please report any errors or bugs to UmaiKeiki in #mahjong.", but I never saw any mention of what irc server he used, so completely useless info?