Do you riichi?

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Mauro
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Re: Do you riichi?

Post by Mauro » Fri Feb 05, 2016 10:07 pm

I won by ron a round later (shimocha 11th discard), so each of them just discarded one tile, but for both was genbutsu. Here's the whole game, if you're interested: http://tenhou.net/0/?log=2016020522gm-0 ... 015ee&tw=0

(I riichied also because 7-crak was suji; it was a good thing, since all 7-crak was in my opponents' hands.)

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Re: Do you riichi?

Post by Krabman » Sat Feb 06, 2016 9:49 am

I don't think our decisions should be judged on the basis of seeing opponents' hands (hindsight bias). During the game, you didn't know they had all 7m. That Ron didn't improve your position & none of the opponents were aggressive, therefore that win could've been skipped in hopes for tsumo which would've given you 2nd place. Frankly, while playing I'd probably Ron too because I suck at math xD

I wonder what stronger players will say about it!

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Re: Do you riichi?

Post by Mauro » Sat Feb 06, 2016 10:00 am

Krabman wrote:I don't think our decisions should be judged on the basis of seeing opponents' hands
Sure, you're right: it's the reason I hide my opponents' hands while posting screenshot, so people replying can't be influenced by them. That was just a side comment :D

I think riiching was right also without knowing where the 7-crak where: I'm waiting on four tiles, reasonably some of them are in my opponents' hands; moreover, also if I tsumo that's a 1000/2000 hand, so it isn't enough to be second. If I riichi I warn them, but on the other hand warning them means maybe someone will start defending: one less player trying to win, and my winning tile is suji.

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Re: Do you riichi?

Post by Krabman » Sat Feb 06, 2016 10:05 am

Yeah, Riichi was a good play but with Tsumo you'd have 2000/3900 ;p

Yeah, that's a great thing to do (hiding the hands) as they can subconsciously influence our analysis.

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Re: Do you riichi?

Post by Mauro » Sat Feb 06, 2016 10:21 am

Krabman wrote:Yeah, Riichi was a good play but with Tsumo you'd have 2000/3900
With riichi tsumo yes, but with only tsumo it'd have been 1000/2000, wouldn't it? Sanshoku and tsumo, it'd be 30 (20 + tsumo + penchan wait) fu 3 han O_o Am I missing something?

Edit: If you mean that I would with riichi tsumo I'd be second you're right; I was referring to winning by tsumo without riiching.

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Re: Do you riichi?

Post by Krabman » Sat Feb 06, 2016 10:26 am

Ahhh ok :) Yes, I'm only considering instant Riichi and a possibility of declining Ron to wait for Tsumo.

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Re: Do you riichi?

Post by Mauro » Sat Feb 06, 2016 10:40 am

Krabman wrote:I'm only considering instant Riichi and a possibility of declining Ron to wait for Tsumo
Uhm... I think I'd ron hoping in uradora, rather than hoping to tsumo one out of at beast three tiles. Do you think the chances for tsumo are better than those for uradora?

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Re: Do you riichi?

Post by DdR_Dan » Sat Feb 06, 2016 8:35 pm

For the first pic:

West wind is safe and you still have a good chance of getting back to tenpai with 1-crak 2-crak 4-crak 5-crak 7-crak 2-dot . 1-crak is furiten but that's okay. I would discard west wind, but given joukyuu room rank point values (+0 for 3rd, +15 for 2nd, +60 for first), 4th being far back and winning or losing would get them out of the dealer seat, and the riichi from 1st place who is not the dealer, I think riichi, discard 2m is okay too.

For the second pic:

Given joukyuu point values I'd give up on 2nd and just aim to avoid last in this situation. Riichi here gives you a slight increase in chance of getting +15pt (2nd) and an increase in chance of getting -60pt (4th). Of course, it's still possible to end up last despite not declaring riichi, but not declaring riichi gives you a better chance to avoid playing in and getting last, and you save 1000 points. If the chances of getting 2nd were better, like you could ron off anyone and get second without uradora, or if you were confident you wouldn't end up in last, riichi is better. 7m being suji might give you a better chance to win if you riichi though.

I agree with calling ron and hoping for uradora.

Also:
ss (2016-02-06 at 11.29.58).jpg
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What would other people do here? 1st is close, 3rd and 4th are kind of far back. With riichi, the hand is pretty valuable, or, I could discard 9m and go for tanyao, but my hand would be full of dangerous tiles, and I likely have to discard 7m for a good tenpai. For this reason, discarding 7m now could be considered. Or I could keep tenpai but not riichi, and hope to draw or chii 2m or 6m, or even call pon on 8p if I really wanted to. I also save 1000 points but can only win by drawing the hand myself, and even if someone riichi's it's hard to fold. 2nd place has more meaning in tokujou rooms (+30 compared to 1st which is +75), but last is brutal at 6th dan (-120).

My actual choice was to not riichi but keep tenpai. West wind riichi'd and discarded 9-dot and I drew and discarded 7-dot , so even though I didn't riichi I wasn't intent on folding completely (I think 4p or 3p is safest because they discarded 1p and it's hard for them to have 5p, and they could have a hand like 899p -> 89p or 779p -> 77p). I think I made the wrong choice, cause I should've riichi'd and kept tenpai or discarded the tenpai, but I'm not sure.

(As for what actually happened, west player tsumo'd on the dora and won a 1000/2000 hand. [Then they won a mangan off of the player to my left and won, and I kept 2nd.])

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Re: Do you riichi?

Post by Krabman » Sun Feb 07, 2016 12:27 am

Mauro wrote:
Krabman wrote:I'm only considering instant Riichi and a possibility of declining Ron to wait for Tsumo
Uhm... I think I'd ron hoping in uradora, rather than hoping to tsumo one out of at beast three tiles. Do you think the chances for tsumo are better than those for uradora?
I think you're right.

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Re: Do you riichi?

Post by Mauro » Sun Feb 07, 2016 11:33 am

DdR_Dan wrote:What would other people do here? 1st is close, 3rd and 4th are kind of far back. With riichi, the hand is pretty valuable, or, I could discard 9m and go for tanyao, but my hand would be full of dangerous tiles, and I likely have to discard 7m for a good tenpai. For this reason, discarding 7m now could be considered. Or I could keep tenpai but not riichi, and hope to draw or chii 2m or 6m, or even call pon on 8p if I really wanted to. I also save 1000 points but can only win by drawing the hand myself, and even if someone riichi's it's hard to fold. 2nd place has more meaning in tokujou rooms (+30 compared to 1st which is +75), but last is brutal at 6th dan (-120)
Is there any reason you would think one of your opponents could be in tenpai?

As for what would I do, I think I'd either riichi, having more than half a game ahead of me, or fold, hoping to keep a good position and aiming to improve it in South 4 (where I could also get a countinuance). I think I'd have riichied, but sometime I'm prone to reckless riichi :mrgreen:

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Re: Do you riichi?

Post by Mauro » Wed Feb 10, 2016 1:39 pm

Not so much a do you riichi, rather a do you push:
20160210.jpg
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I'm first with with a small lead; I could discard 137m, with 37m that could be dangerous. Kamicha could be tenpai, possibly with a small hand (barring dora; I don't give him honitsu), but if I pay my lead decreases. South 2, so still some game ahead of me, but not necessarily so much.

Let's say I discard 1m: if next turn I draw another dangerous tile, should I push?

(I discarded 7m - not noticing 1m was as good - and paid 1500; in South 4 toimen won a 12000 hand - bringing the game in West 1 with me first with 29500 - and another 6000, ending first with me second.)

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Re: Do you riichi?

Post by DdR_Dan » Thu Feb 11, 2016 7:45 am

I would discard 1m to start, and then decide based on the next tiles. If I got to tenpai (I would probably call if it would get me there), then I'd discard the 7m because it's hard to use with 3 6m and 3 9m out, but if it gets called or ron'd I'd be worried about a possible dealer toitoi. 3m is safe for this turn, but not only that, you can see all 4 2m, and shimocha discarded 6m, and you can see 3 3m, so discarding the 3m should never help them: If they had 45 wait, they wouldn't discard 6, they can't have 12 or 24, and they can't have 33. It's possible toimen needs 3m, but their hand isn't likely expensive and they aren't the dealer and there aren't any warning signs like them discarding 4m or 5m from their hand last discard either. I wouldn't expect them to be in tenpai either. So, if I got to tenpai, I'd use 3m and 2m as safe tiles if I drew some tile I thought was especially dangerous.

I'd guess that shimocha isn't really that close to tenpai because their discards are nearly all terminals and honor tiles, and I'd be okay with discarding 123689m, 25789p, and any bamboo tile. I'd be uneasy about discarding 134p maybe 6p, and 457m, and white dragon and west wind. These are because the dealer looks closest to tenpai, 134(6)p are near their last discard from their hand, and 457m look risky for potential toitoi. If the 2p was discarded after a call, then 6p isn't so dangerous (it's dangerous if they have 24p and draw 5p). No white dragons discarded makes white dragon look really scary.

Bamboo tiles being safe for the dealer's hand is kind of a read, but most people don't discard 98, then draw and discard 4 while not near tenpai or in tenpai, and still need many tiles in the suit. If you had 66s and extra pairs (66m) more often you'd keep 668 or 466. And, usually you'd hold the 4 with 455 or 433, and maybe with 422. Two 1s are out so they can't have 11 if you draw the third either. Another way of thinking about it is when you discard 98, often times it's cause you have 65. But if you draw and discard 4, you didn't have 65, and you probably didn't have 12 or 13 (you'd discard 1 instead), so there aren't many waits that make sense. But people in this room can play more unpredictably, and, it's not a guarantee either. In some situations it could make sense to have a bamboo tile wait.

For the character tiles, 4 2m, 3 3m, 3 6m, and 3 9m visible, and certain character tile discards make it really hard to have run waits in the suit. If the dealer does, their hand is likely cheap as it wouldn't be toitoi. Just white dragons, red dora, and unusual honitsu would make it expensive.

Also, I just realized I can't see the timing of the red dragon discard from the dealer, but that would have a lot of meaning as well.

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Re: Do you riichi?

Post by Mauro » Thu Feb 11, 2016 9:03 am

DdR_Dan wrote:It's possible toimen needs 3m, but their hand isn't likely expensive and they aren't the dealer and there aren't any warning signs like them discarding 4m or 5m from their hand last discard either
Why do you think their hand isn't expensive?
If the 2p was discarded after a call, then 6p isn't so dangerous
Why's that? Because it isn't near 2p?
I can't see the timing of the red dragon discard from the dealer, but that would have a lot of meaning as well
Just after 2p.

By the way, I'm playing without red dora, so it's even more likely the hand isn't expensive.

Thanks for the reply, it's really interesting!

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Re: Do you riichi?

Post by DdR_Dan » Thu Feb 11, 2016 10:50 pm

Mauro wrote:
DdR_Dan wrote:It's possible toimen needs 3m, but their hand isn't likely expensive and they aren't the dealer and there aren't any warning signs like them discarding 4m or 5m from their hand last discard either
Why do you think their hand isn't expensive?
You can see the dora so they don't have dora, and their hand doesn't look like a special high value hand like honitsu/chinitsu, closed junchan. Sanshoku which is normally rare is even harder with the character tile suit distribution. So it's hard for them to do better than pinfu + tanyao + iipeikou, and even that isn't very likely. So I wouldn't worry too much about them unless they riichi, because it's pretty likely they won't even be in tenpai.
Mauro wrote:
If the 2p was discarded after a call, then 6p isn't so dangerous
Why's that? Because it isn't near 2p?
One reason to hold on to and then discard 2 is because you have 24, and then you draw a 5, and your wait changes from 3 only to 3/6. If you instead call and then discard 2, you didn't draw a 5 so that didn't happen. Things like 112, 122, 223, 233, 244, 224 are likely if the 2 was connected to a wait. Sometimes it can just be a lone 2 though. One other possibility is 246, and now the 5 could be their winning tile.

For specifically needing the 6, if they had 45 you would expect them to discard the 2 because it's not that helpful. If they had 668 or 578 or 788, you'd expect them to hold on to the 8 rather than discarding it earlier. So 6 is more likely safe unless they had specifically 24 -> 45. There are still unusual cases where you might end up needing a 6 while playing pretty efficiently, and some cases where the person might play their hand strangely.

Maybe something like:
:south :south :south 6-crak 6-crak 2-dot 3-dot 6-dot 6-dot 8-dot 2-bam 2-bam 8-bam 9-bam Discard 8-dot
:south :south :south 6-crak 6-crak 2-dot 3-dot 6-dot 6-dot 2-bam 2-bam 8-bam 9-bam 2-bam Discard 9-bam 8-bam
:south :south :south 6-crak 6-crak 6-crak 2-dot 3-dot 6-dot 6-dot 2-bam 2-bam 2-bam 3-dot Discard 2-dot for toitoi

Mauro wrote:
I can't see the timing of the red dragon discard from the dealer, but that would have a lot of meaning as well
Just after 2p.
If they held the red dragon and then discarded it, it's more likely they have fixed 2 sided waits and the tiles they discarded earlier might not be connected to them, is what I think. If they drew and discarded it, it's hard to say much about their hand besides 2p being the last discard from their hand so that area would be more dangerous. They also are committed to their hand and are probably in tenpai, but if they aren't actually in tenpai, they must be keeping a tile that they believe is either useful, or safe, and you should be able to tell from the discard from their hand. If it doesn't look like a safe tile, the tiles in that area (+-2 numbers) become really likely to be their winning tiles.
Or, they might not realize red dragon is dora and hasn't been discarded. :D


By the way, I'm playing without red dora, so it's even more likely the hand isn't expensive.

Thanks for the reply, it's really interesting![/quote]

Something I just realized is I think like this as much as I can when people don't riichi, but when they riichi I think completely differently. Maybe I should use this thought process more to play more aggressively against other players' riichi.
Last edited by Shirluban on Fri Feb 12, 2016 10:37 am, edited 1 time in total.
Reason: Fixing quotes.

Mauro
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Re: Do you riichi?

Post by Mauro » Fri Feb 12, 2016 12:05 am

DdR_Dan wrote:Sanshoku which is normally rare is even harder with the character tile suit distribution
Do you mean the tiles visible on the whole board?
One reason to hold on to and then discard 2 is because you have 24, and then you draw a 5, and your wait changes from 3 only to 3/6. If you instead call and then discard 2, you didn't draw a 5 so that didn't happen. Things like 112, 122, 223, 233, 244, 224 are likely if the 2 was connected to a wait. Sometimes it can just be a lone 2 though. One other possibility is 246, and now the 5 could be their winning tile.
Does the type of call (run in the same suit, in another suit, pon) change how much dangerous 6p (and, in general, the tiles near 2p) is?

About the red dragon, I checked, and it was tsumokiri (if you want, tomorrow I'll get the link to the whole game and post it here).

Thanks!

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