Ura Suji

If you don’t know what suji are, you should start with Basic Suji. This suji builds on that knowledge.

Ever heard of ura suji or “back-facing suji”? We hear “suji” a lot but almost always about the regular or omete/front-facing suji and not nearly enough about ura suji.

Ura suji aren’t about telling you what is safe but telling you what is dangerous.

To understand what creates an ura suji, I think it makes sense to understand how they get created when building a hand.

Let’s say you have 245 in your hand. That 2 is likely to be cut as your hand progresses from an efficiency perspective in that there is likely to be relatively little loss in throwing a 2 compared with other tiles and due to the 45 shape being more optimal for the number of outs.

That means if we see a 2 in the discard pile, it is possible that the player is waiting on 3-6. We can extend this logic for the whole of a suit. Basically, it’s one tile next to the discarded tile and then its regular suji friend on the other half of the suit.

There is a pleasant symmetry in ura suji if you take the five as the mirror. Hopefully, that makes them easier to remember!

Reading ura suji on a discard tends to work better for tiles thrown in the first 12 discards of the game. But that is not a hard and fast rule.

Again, like regular suji, there is an assumption that people are optimizing for two-sided/ryanmen waits (upgrading their inside/kanchan waits. It might save your bacon when you’re sat there with a hand of tiles that look very unsafe and you’re pushed into a choice.