Haipai Efficiency – Part Two
We continue our series with a look at terminals. Unlike honors tiles, terminals don’t intrinsically differ in value. Instead, what sets them apart from each other is the rest of your hand.
Terminals
Let’s suppose you had the following starting hand. Setting aside ittsuu or junchan, what would you discard first?
Before we reveal the correct answer, let’s first establish a few basic rules that you can use to compare terminals against each other.
- Terminals for which you hold the middle suji decrease in value compared to an isolated 1 or 9. If you have 69 and you discard the 9, you can still make use of 7 or 8 if you draw them.
- When you have a 5 in that suit, terminals increase in value compared to an isolated 1 or 9. For example, the 9 in 59 is more valuable. This is because drawing 7 gives you a ryankan shape waiting on two tiles.
- Terminals that are next to a taatsu such as the 1 in 124 or 134 either increase or decrease in value depending on whether or not you already have a pair or another shape that can easily produce a pair. If you do, such terminals decrease in value; if not, they increase in value. This is because drawing either 3 or 2 respectively creates a nobetan wait.
With this in mind, let’s compare the terminals in the hand above. Making use of these three rules gives us the following ranking:
> > >
The correct discard is therefore .
Practice time! Take a look at the following hands and see if you can identify the most useless terminal tile in each one.
Feel free to post your answers in the comments!
9m
1m
9s
The fact that I have little faith in any of my answers being 100% correct would probably suggest I should work on this a bit more!
Hello.
The first one is a straightforward 9m discard. You lose out on nothing but another 9m that way – considering you only have three (potential) sets so far in 456s 56p and 34m the aim is to have a discard that leaves you the biggest variety of tiles to complete another set. Discarding something else isolated like the 9p loses you the 7p and 8p whereas discarding 9m you lose nothing as you still have a (relatively) isolated 6m remaining to integrate 7m/8m.
The second one is an 1m discard. As by what’s been said above, the 59p gives a 579p ryankan chance, whereas for the first shape you can consider it, efficiency-wise, a 567m with isolated 1m and 4m. Drawing 23m does nothing for you.
Third would be 9s – you want to keep the potential for a 6789m or 1234p nobetan open considering you don’t have a pair, so it’s none of those terminals. Discarding 9s you still don’t feel bad drawing 7s since it completes your other taatsu, so you only lose out on 89s, whereas discarding 9p would make you lose out on 789. (In reality you still wouldn’t be very happy drawing 7p for a 79p kanchan, but that’s a different issue).
If, given 59m 9p, we prefer cutting 9p for the chance at ryankan, does that imply that we prefer 579m 15s 3p over 57m 5s 139p?
It’s not quite an even comparison. In cases when you don’t have enough blocks, it’s more important to get more blocks than to have a few blocks with a good-ish shape. Although the 1 in 15s is more valuable than an isolated 9p, it’s not more useful than a floating 3p with which it’s easier to form a another block.
There’s a bit of complexity regarding floating tiles and kuttsuki iishanten, but I hope to cover this in a future article.
What are your thoughts on the 9 in 679 or 689 vs a lone 8 in a hand that has no pair? Say 13689m 13579p 1258s, or similar? Then, what about the 9 in 679 vs a 9 in a 79 or 89 wait? Same as other example but 13689m 13579p 1279s.
Also, what about 2 vs 9 in a 259 case?
1. It takes a lot for a 9 to become more useful than an 8, which I hope to cover in part three of this series. The nobetan chance is not enough, so just discard the 9m.
2. I’d discard the 9m here too. It’s harder to complete blocks than to form a pair, so leave the latter until later.
3. This one’s a bit more marginal. 2 loses a bit of value since you have the middle suji 5. Discarding either of 2 or 9 loses only 12 and 89 ukeire respectively. Drawing 3 or 7 gets you a two sided wait either way, but ryanmen is better than ryankan so the 2 is more valuable in the end.
Just play the game and stop thinking so much.
Unless you have X-ray glasses and know every tile you are going to draw each turn, you are going to lose matches sometimes anyway.
Life is too short for all this theory.