A question on waits?

[or2az]

Is it better to discard the and wait on the , IF ALL 4 OF THEM ARE STILL AVAILABLE, or
to discard the and wait on the , IF BOTH TILES OF EACH ARE STILL AVAILABLE.
Meaning, do you put all 4 eggs in one basket, or spread them out with 2 baskets of 2 eggs each?
Also, are there any other factors that would affect your decision, like if the pair were terminals, or honor tiles? or the point score?

[Moah]

I'd discard the because it's better to have different tiles when waiting, and in your specific case you get another 2 yaku on tsumo (san an kou).

[Referee]

In this case of San Ankou it is right. But I like because it can be improved to or

[or2az]

Didn't realize I made up a fictitious hand where San Ankou would be a possibility.
How about this variation with a riichi situation where no improvement on the wait can be made. Same reasoning?

[Iapetus]

But I like because it can be improved to or

Think again. can be improved with .

In this case, if you were to riichi right away, shanpon has one notable advantage: suji traps. Drawing 6p or 4m makes one of your winning tiles suji. For the kanchan you would need to draw both 17p.

But in a general situation, I think the kanchan would be more likely to win. That's because with only two 7m but all of 5689m left for your opponents, the 7m are likely to be tied up in other hands, serving all those 5689m. Same for the 3p and 1245p. This means that they're less likely to be discarded, both before and after riichi, and thus also that you're less likely to draw them. Of course discarded tiles can utterly change this factor. And it's probably not a big advantage, but if the decision is otherwise 50/50, you have to take it. Or maybe everything I just said is nonsense, does anyone else have any knowledge on this?

[or2az]

Stop! Take a breath! I'm afraid you lost me. I didn't realize that the answer to a simple question like; What would you rather go for on riichi, one tile, the , of which there are 4 available, or two tiles, , of which there are 2 each available, could be so complicated. Seems to me like you are overthinking the situation, which is ok, but it is all speculation and guesswork. I mean, someone might be holding the pong of in their hand in which case you might never get one. As Mr. Spock would say, "The possibilities are endless, captain".
Let's see what kind of replies you get.

[Referee]

Iapetus is right, but what is de dora? If it's 7m, then I like my answer better. However, the big factor is those vs . How many are available?

[Iapetus]

It's certainly all situational. You're best off looking at what tiles have been discarded and making the decision based on that. Picking kanchan over shanpon would be your last resort. Although with the 4p ankou counterexample, I have no idea. One would need statistical research, but the result would be almost meaningless.

[shinkiii]

It depends on the shanpon wait imo. The potential for suji trap won't be enough against more experienced players who have the discipline to play full defense. I'd probably just choose kanchan wait regardless, but that's not a very strong play in the second example hand. The only time I would choose shanpon is if one or both pairs were kabe-blocked by other tiles (such as waiting on 1p/4s when all four 3p have been discarded).

I saw a mahjong pro (Tsuchida Koushou) who has a "toitsu theory" translated on osamuko, an english mahjong blog site. That theory, very roughly, is as follows:

Most likely pairs are 1, 9, and off winds
next are 2, 8, seat wind
next are 4, 6, dragons
next are 5, round wind
least likely are 3, 7

There are additional things about hand/tile shapes and the idea itself here (very interesting even if you do not agree with it!): http://www.osamuko.com/tsuchida-koushou-homage/

The only reason this theory, which sounds like total occult bs, is talked about at all is because tsuchida koushou was one of the strongest professionals in Japan, and because it's really just a way of organizing information. Middle tiles and the 3/7's are more likely to be useful for player's hands, and honor tiles are more likely to be kept until later in the game, meaning you have less information about whether they're still in the wall or not. Edge tiles are more likely to come out first, meaning that if they still haven't been discarded later on in the game, it's more likely that they're still in the wall or that they're being kept to go after a yaku like chanta. Even though this is a chiitoitsu theory, it can apply in much the same way for getting extra tiles of the same group through understanding where the other tiles are (used by other players vs. in the wall).

Basically, in both examples, even with the chance of getting san an kou, i'd still take the kanchan wait almost every time. It has equal potential of naturally creating a suji trap, it doesn't assume that you'll draw a tile that will improve your wait, and it's still a hand that has a good chance to get mangan in both cases. If you wanted to distill it into a few general guidelines...
-1/9/off wind shanpon is ok
-kabe-blocked shanpon is ok
-suji trap shanpon is ok against opponents who rely too heavily on suji
-otherwise, kanchan is less likely to leave you in karaten (empty tenpai)

[zzo38]

There are many things that may be considered. The "toitsu" theory is something I have not considered before, but now I can see how it can work.

Another example is, if you have "1234p" and you have to discard the 1p or 4p and declare riichi (with the same waits either way), then I would think these are possibilities to consider:

• Yaku, for example depending on the rest of your hand, discarding 1p may be tanyao
• What is the dora
• Defense, don't deal into other player's hand
• Trick opponents so they don't know what you need to win
• Which is less likely to be ura dora
• To make opponents not know which tiles are available if one is more likely the kind they would be looking for to know which way to improve their hand

These things may apply in other examples too, possibly even the others in this thread, although they are different so some considerations are going to be different. Maybe I have missed something, but it is one situation of what to discard to tenpai.

[or2az]

I have a question regarding a game situation that has occurred more than once for me. Suppose my hand is exposed except for .
I am waiting for a or a for the tanyao win.
I draw a from the wall.
I cant keep it because my hand is open and when I discard it, I am in furiten. Now I cant claim the 4 or the 7. NO FAIR!! I didnt have a choice.
Is this what they mean by " being caught between a rock and a hard place " ?
I know I can still win by tsumo but something doesnt feel right. Its not like I discarded the 4 or the 7 earlier in the game (which would be winning tiles); I discarded the , which was not a winning tile (even though it does complete the hand). Am I missing something?

[Referee]

The fact that it completes the hand, even without a yaku, is all that matters for the rule. You are in an unlucky furiten situation. Hopefully you can get out, for instance ponning your head, which you haven't shown and I assume to be unrelated, and then discard to wait on , out of furiten.

An equally unlucky scenario could come if, say, your RHO would have discarded , which you can't claim because you are yaku-nashi, and then the player in front of you discards , which you can't claim because letting the ippin go made you furiten.

Those are the risks of opening the hand too lightly.

[Gnom]

That's why opening a tanyao-only hand if there's a possible wait with a 1 or 9 is dangerous :p

In this situation, depending on the situation, I'd either:
-just wait for a tsumo or just stay tenpai, for example if it's o-rasu and I'm oya in last position, which would allow me one more chance
-try to change my wait, could go to a double 2-5 or 3-6 wait after ponning my current head for example
-most likely fold my hand, I mean we're talking about a 1000 points hand here.

In either case, I'd also curse myself for good measure

An equally unlucky scenario could come if, say, your RHO would have discarded , which you can't claim because you are yaku-nashi, and then the player in front of you discards , which you can't claim because letting the ippin go made you furiten.

Although unlucky, this situation isn't as desperate since after the next draw you wouldn't be furiten anymore, so you would have only wasted one of your (max) 7 winning tiles...

[or2az]

Both of you have mentioned "ponning your head". Not sure I know what that means. Can you explain?
I know it doesnt mean banging my head against the wall, which I felt like doing.

[Gnom]

You got it right, in this context "your head" doesn't literally refer to your head but to the pair of tiles that completes your hand. If you change it to a pon and discard one of the outside tiles of the pattern you're waiting on you can get a two sided wait with a maximum of 6 tiles available, so depending on your need to win this hand and how dangerous the tiles you have to discard to get there are this might be a good compromise. Hypothetically you could choose the 2/5 wait rather than the 3/6 and get a small chance at getting an akadora.