Choosing Riichi Waits (1)
Over the next two pages, let us think about how to choose a wait when declaring riichi.
Judgment 1: Number of Winning Tiles
When the number of winning tiles differs, choose the side with more winning tiles whenever possible.
Example 1
Draw 
If you cut ,
you can make it a wait on 
.
But a 7-tile wait is better than a 4-tile wait,
so the correct answer is to cut and riichi.
Also, remember this souzu shape. It comes in handy from time to time.
Judgment 2: Point Value
When the number of winning tiles is the same, the higher-scoring option is better.
Example 2
Draw
Cutting , , or
all create the same 4-tile wait.
If that is the case, then riichi after cutting ,
so that you still have the possibility of tsumo sanankou.
This pinzu shape is also worth memorizing. It is very useful in practice.
Judgment 3: How Easy the Wait Is to Discard
Example 3
Draw 
If you cut ,
you get a ryanmen wait on .
But there is another discard candidate.
If you cut ,
you can make a wait on 
, , and .
Both options have 7 winning tiles, and the point value does not change either. So which wait should you choose for riichi?
| Ease of Being Discarded | Tiles |
|---|---|
| A rank |   |
| B rank |   >   |
| C rank |     |
| D rank |    |
| E rank | to  , to  , to |
| F rank | Dora and dora indicators |
There are real differences in how easy tiles are to discard, which means how easy they are to ron on. The table above is a good rough guide.
Strictly speaking, even the tiles from 3 to 7 have small differences, but they are minor enough that you do not need to worry about them much.
Tiles that are harder to use efficiently tend to get discarded more often. In other words, yaochu tiles are easier to ron on.
So in Example 3, compared with waiting on the hard-to-discard E-rank tiles ,
it is easier to win by waiting on the easier-to-discard .
That means the correct riichi is to cut .
Example 4
Pon 
How easy a tile is to come out is extremely important. If you understand it, it creates edges in many situations.
In Example 4, if you look only at efficiency,
it may seem better to cut and allow a future tsumo to make a ryanmen.
But purely in terms of how easy it is to ron,
it is absolutely easier to take the shanpon on .
This is an important piece of knowledge, and you should be able to use it in real play.
Example 5
Draw Dora
Between a kanchan wait and a shanpon wait, the shanpon is generally superior.
In Example 5, unless the table situation strongly suggests otherwise,
riichi after cutting will usually win more often.
Why? Because anyone with even a basic understanding of mahjong chooses their discards against riichi.
When you riichi on a wait that is not ryanmen, tiles often come out later because of suji and kabe reasoning. Those become your ron tiles. See Chapter 7 for more on that.
In this hand, if you choose the shanpon, the relevant "effective tiles after riichi" include:
- Suji from
- Kabe from
That gives six different relationships that can make your winning tiles come out.
If you turn it into a kanchan instead,
then the only effective tiles after riichi are
.
And if you riichi after cutting ,
then whichever of those appears on the table,
opponents are likely to become more wary of .
For those reasons, when the choice is between shanpon and kanchan (or penchan),
shanpon riichi is the basic theory.
Of course, there are still many situations in real games where the kanchan is better, so you should stay flexible.
Original Japanese page: http://beginners.biz/reach/reach07.html