Not Using Suji
Using suji to divine dangerous tiles does not work when your opponent is doing something irregular.
I’ve managed to avoid unnecessary drama after the riichi with a fully safe 7-pin throw and then a nakasuji throw with the 4-pin. Has the moment come where I have to decide to push or fold…?
We can work out some information from this discard pool. Although it’s devoid of bamboo tiles, it is unlikely to be a flush hand considering the way they brutally discarded (on ron2, shaded tiles are instant discards).
To be able to use suji we need to be sure they’ve built their hand around two-sided waits. There are a few indications that this player hasn’t done that. The two North and the two West all came out of this player’s hand. That’s very odd and not what we’d expect if they were taking the most direct route.
The 4-man was held until they reached tempai and this must form some element of their final shape. If the 5-man throw wasn’t there, I would suggest using matagi suji (straddle), making the 2, 3, 5, 6 man were dangerous. The assumption being that they’ve thrown either from a 344 shape or a 445 shape. We can’t know that this is where they’re waiting but normally we could mark these tiles around it as dangerous. Subsequently, I would not be able to easily throw my 3-man or 6-man. However, the 5-man throw on the sixth discard makes it highly unlikely that they completed or are waiting on a two-sided wait around that shape OR they’re furiten.
Now we have to wonder what shape they threw this out of. The likely candidates are a 22-4 shape and they’re waiting somewhere else with the 2 as a pair for their hand or perhaps even a two pair wait (shampon). Or a 2-44 wait and they’ve decided to wait on the 3. Both of these beg the question, though, why did they hold that 5-man and then throw it… They must have been massaging something that was likely not a pinfu.
There is a faint possibility that the player has a 4455 shape and for some reason decided to prune it down to a single run. I’ve got a 4 and a 5 myself so that makes it a little less likely, but it is possible.
Did I answer the question about whether I could push or whether I should fold? Not really… However, the 4-sou discard gives me some confidence that whatever they’ve done here, it probably doesn’t have a dora bomb. I am East with 40k points at this stage in the South round so I would like to pull myself further ahead if possible. Considering what my read is, the 6-man is not the worst discard. It’s not safe by any means and I am clearly pushing at that point, but out of my options to discard, it’s probably the better one if i’m absolutely determined.
Going back through the replay…
I guessed almost right! This player was doing some interesting stuff. We can see how it came about if we look at the starting hand.
They start trimming in a fairly regular way. I’d personally hold onto the West a little longer as it is their seat wind.
This is the point where the player’s direction makes a sharp turn. They have a value pair, and two dora. So they start to trim away the Norths as they already have two other candidates for the pair (the 4 pin and the South).
It’s here that they lock themselves in. Rather than giving themselves as wide a shape to take tempai, they instead hold the West and throw the 5-man. They’re at the bottom of the points right now so they’re hoping to lock in that they will have a triplet of South, and that they don’t want to wait so close to the centre (in the hope that someone will throw in). I don’t think this is how I would play personally, but it certainly made for a harder discard pool to read!
Takeaway: Use suji judiciously!