Analysis - Wait Win Rates by Row

Previously, we looked at the wait win rate of every riichi hand. This time, we'll look at the wait win rate of every riichi hand, separated by row.

The chart is much the same as in the previous post, but the methodology is a bit different. The results are sorted into four different buckets. If they had zero discards when calling riichi, it went into the Double Riichi bucket. If they had less than six, it went into the First Row bucket. If they had more than six and less than twelve, it went into the Second Row bucket, and if they had twelve or more, it went into the Third Row bucket.

Additionally, only first riichis were counted, not chasing riichis.

For an example, let's look at how the win rate of ryanmenside wait shapes changes as we progress through the stages of the game. As a reminder, the columns label how many of the wait are visible, either in discards, the hand, or dora indicators.

Double Riichi

First Row

Second Row

Third Row

I don't think anyone is surprised to see that the win rate goes down the longer into the game you get. For these ryanmenside wait shapes, the win rate goes down by roughly 15 percentage points for each row.

In the Double Riichi section, we can know things more solidly because of how little options there are. A ryanmenside wait shape with 4 out is probably a shanpondual pon wait, and with 5 out, a shanpondual pon wait with the dora indicator or an early discard involved. The 4 and 5 outs for the ryanmenside wait shapes only have 71 instances, out of 8966, so these are minor.

Using this data, we can also roughly estimate what the wait type is at each stage in the game.

The "Other" section is probably mostly various shanpondual pon wait shapes, with some complex shapes in there. The frequency of a single wait (either tankipair wait, penchanedge wait, or kanchanclosed wait) isn't that much higher when you compare the first row with the second row. I was curious how much of those single waits were honor tankipair waits, so you can see that at the bottom. It's drastically higher for double riichi.

Check out all of the data in this spreadsheet. Until next time!