Riichi Mahjong in Singapore

This is our 1st WWYD question with situation analysis!

This is a rather intermediate question that tests your balance between offence and defence. There are many discard reading skill required here but are quite familiarised by veteran players (I believe). Just that, it is not easy to identify and use all the skills in order to conclude your choice of discard in this situation.

The dot indicates Tsumogiri. 8sou was pon-ed and 3s was discarded. Aka-nashi rules.

Source: 二階堂亜紀の勝てる麻雀ー守りの基本, ページ 127

Nikaido Aki’s Answer (Added 2 months later)

This is a very intense state of game. Before we consider what discard to make, let’s think about what the opponents are doing.

Firstly, Nancha has made a meld of Ton, and 2 melds of Pinzu sets. Usually, we should be wary of Honitsu but the very first discard was 8p, resulting in a lot lower possibility of it being Honitsu.

Of course, there is a possibility of changing its course. That means the hand will probably be something like this: 4567p Because 8p wait will result in a Furiten, it probably doesn’t have a 67p shape. So if it is Honitsu, it is likely to be 47p wait. However, 4p was discarded 2 turns before so this possibility becomes extremely slim.

What about honour tiles? Most of the honour tiles have 2 or more being discarded. The only two left are Nan and Sha. Nan was just discarded. Therefore, this eliminates the possibility of a honour Shanpon wait.

Since this is an aka-nashi rule, it is most likely that Nancha has two doras, with a Manzu two-sided wait.

It is difficult to see from the picture but after Shacha discarded a pair of 8m, Nancha discarded 8s from his hand for Shacha to pon and discard 3s. This means that 8m has not been proved safe to Nancha yet.

Shacha is not as obvious as Nancha but it worth a lot of attention because Shacha has 2 melds. Although the early discards were 9s and Pei, I wouldn’t conclude a low possibility of a single-suit based hand. This is because Shacha has discarded a pair of 8m from hand. 8m wasn’t discarded because it is safe (it is live), and it is a good pair to be kept for Toi-toi. Furthermore, the 3rd copy (from discard pool) of 3s was then discarded from hand. So it is rather conclusive that it is as Souzu hand.

While it is a little difficult to deduce the actual shape of the tiles beside 3s, the wait is definitely around 3s, which is 1245s. This means any of these Souzu at this stage cannot be discarded anymore.

As for Peicha, reading a concealed hand is extremely difficulty. What’s worth noting is the discard of a live Nan. If this tile was discarded as move of pushing for a win, then it is best to assume that Peicha is in Tenpai. If in the next turn, another Nan is discarded then it is fine to conclude that Peicha has bailed.

The above are all simple reading if one can grasp the general situation of the game. So what should be discarded then?

Against Shacha‘s last discard of 3s, it is clear-cut that 12s cannot be discarded.

Against Nancha who has the remaining hand full of Manzu, 56m cannot be discard.

Discarding Pinzu will result a hand further from Chiitoitsu, and also not safe to Peicha.

There’s no other way but to discard 6s here. 6s is Nancha‘s Genbutsu and 36s has passed for Peicha. Although it is possible for a 69s wait, with 3 8s seen, 6s is considered one-chance. As there are no other safer tiles available to discard, it cannot be helped with 6s deals into the hand.

What about Shacha?

If it is Kan-6s wait, it will be discarding 3s from a 357s. Since Shacha has ponned the 6s, there is no reason to choose to wait on 6s instead of 4s. So 6s is safe against Shacha as well.

This may not be used to some to give up this decent Menzen Iishanten hand as an Oya, there are some crucial points that must not be forgotten. With 8s being ponned, the 67s Ryanmen is effectively a single-sided wait. Plus, 56m is an extremely risky tile to be discarded to Nancha. Rather than viewing this hand as an opportunity, it is more of a crisis.

Feng’s personal take

Based on what I hearsay from players’ viewpoint regarding this question, there was an issue raised but may not be properly addressed by Nikaido Aki (or at least, this page).

[There’s no more safe tile after 6s discard. What would you discard after 6s then? How worthy is it to trade away this 1shanten shape for just 1 turn of safety?]: To players who may have been arguing over this point probably come to the same conclusion as me after reading Nikaido Aki’s analysis. The problem of this situation is that, there are 2.5 attacking players. The 0.5 player refers to Peicha whom we are not very certain that he is bailing or pushing with Nan discard. It is fundamental that, as much as possible not to join the fight of other 2 or more players. By “fight” refers to them being in Tenpai. That’s why this situation is described as a crisis rather than an opportunity by Nikaido Aki.

Therefore, even if the next discard is something dangerous, such as 7s, 2s or 6m and allows you to reach tenpai, my personal take is to push with relatively safer tiles. This hand has 0 fighting potential and also risky to commit into a Riichi. Not declaring Riichi will make the hand too cheap as well. The discard of 6s allows you to buy 1 turn to find out whether Peicha is bailing or not as well. If is still unknown (for example, he draw and discard a safe tile immediately), I would think there is no other choice but to discard 8p. 678p are all 1-chance to Peicha. But 8p discard provides slightly more protection since you holds 2 7p on top of seeing 3 6p.

Hope everyone has some takeaway from this!