Concealed vs Exposed

Tile efficiency works just okay for one’s own hand, but what about the tiles that flow out? Obviously, you shouldn’t call every single one of them, but that doesn’t mean you should ignore them either. How to judge? What to consider when calling? Well, the basics are sumed up in the following text.


Basic judgement for calling tiles

Based on what we learnt last time, to call a tile? to not call a tile? let’s think about that judgement.


2m4m5m7m4p8p1s2s6s8s9s7z7z Comes out: 7z Dora: 3p

East one, No-Dealer and you have a hand like ex1. In the third discard 7z came out.
Call this tile?

Let’s see the merits and demerits.

You secure 1 fan, so it gets easier to win.

Defense power falls.
It will only be worth about 1000-2000 points.

To call or not to call,
comparing the merits and demerits of calling, judge which one is bigger.

Picture a scale like the next one:

If the the scales were tilted towards the left: call; if the scales were tilted towards the right, then don’t call.
The important thing here is that the relative weight of these values, changes according to the situation.
Judgements like “There are more merits than demerits” cannot just simply be made that easily.

Let’s give it another small analysis.

2m4m5m7m4p8p1s2s6s8s9s7z7z Comes out: 7z Dora: 3p

Speed:Certainly having 1 fan secured it becomes easier to win but、since it has bad shape even if you call there is a high chance you won’t win. ⇒ The “speed” merit is of low value.

Defensive Power:If you want to win this hand there is a high chance you’ll have to call more tiles, and the your tenpai will come really slowly, so it’s extremely dangerous. Now we are not holding even one dora. ⇒ Defensive Power Down’s demerit is huge.
Point Gain:There is a high chance for 1000 points、but even menzen this is a cheap hand ⇒ Point Gain Down’s demerit is relatively low, but the value is cheap.

Afterwards you have to consider what go-around this is, and whether you’re dealer or not, East round or not, but
it will mainly become like the next image:

The scales are tilted towards the right. This means, it’s better not to call.


2m2m4m6m7m7m2p3p4p5s7s8s8s Comes out: 6s Dora: 7s

East 1, you’re dealer, you are on second place with a 2000 points possitive, and it’ the sixth turn,

let’s suppose the person to your left has discarded6s .

Speed:Drastically up. Even if you get to a concealed tenpai, 6s is a difficult wait to win on.

Defensive Power:Even if we call all tiles, we’ll be ready with just two calls. Furthermore、since it’s only middle tiles in this hand the Defensive Power is weak even concealed.

Point Gain:With menzen riichi it will be 7700 or more, so it’s greatly reduced.

If you win as dealer you can continue, therefore the merits to call this tile are higher.
It is clear that it is better to call.

Like this, thinking about the merits and demerits of calling,
all situational judgements become basic.

People who are strong at mahjong, have these scales very well calibrated and balanced and are therefore strong.

PS: Yeah, they were scales and not equations in the original text, but I sure as hell ain’t drawing and uploading scales at 1 AM. Text form will do. Aaaand, I’m also working on an other translation project right now too involving puyo’s blog. Check RM tomorrow and you’ll see what I mean. Anyhow, until next time~ I’ll probably will touch the subject of KAN.

EDIT: Now they -are- scales~ Thanks, Osamu~

13 thoughts on “Concealed vs Exposed

  1. “…Yeah, they were scales and not equations in the original text…”

    I understand that it is tedious to translate those Japanese pages. Thank you for your hard word. Nothing forces you to do it, let alone at one in the morning. Again thank you very much. However, I think it’s important to warn readers, at the beginning the post, that those formulas have not any scientific basis nor mathematical precision. They are substitutes for the scale illustrations found in the original Japanese text. You might want to tell them to refer to the original drawings, if they want to fully grasp the demonstration.

    The author illustrates his point with a relative, imaginary scale, an allegory for common sense and judgment. He essentially says experienced players evaluated their winning chances by guesstimating which of “speed”, “hand value” and the “ability to defend oneself”, or a combination of all three, is the prevailing parameter to take into account when assessing a game situation. And, he gives some pointers how the importance of those factors vary depending on the situation.

    By substituting those “educated guesses” with formulas, some readers might be let to believe they were somehow scientifically derived. Furthermore, they suggested a mathematical precision, which is not the case, making the text confusing, especially for inexperienced players, the category of readers who have to most to gain by this post.

  2. >PS: Yeah, they were scales and not equations in the original text, but I sure as hell ain’t drawing and uploading scales at 1 AM.

    We have monkeys to do that stuff if you ever need help! Just ask in the IRC channel.

  3. Well, Archangel, I did want them to be led that way a little too, as simply reading this and assigning values to speed, defense and the like, and then comparing them would make them feel “oh, I’m so smart, I’m playing so digital, I’m a genius.”

    It is a given that the values for each term are also educated guesses, just as much as the weight for each item was in the scales. Let’s give the reader a little more credit, and assume they are intelligent enough to realize it is the player who gives a value to those x’s based on their judgement, and the better their judgement is for those values the better players they are. I think no one will take it literally and ask “…how do I know which value to add to […]? Then again, if they were going to, oh well, they are just reading this here now.

    The warning -is- there at the end, anyhow.

    Osamu, I never seem to find the winged monkeys. D:
    If someone draws the scales or at least replaces the text and re-uploads them, I’ll add them to the text and modify the wording.

  4. If I remember correct, February issue of kindai mahjong had a lot concerning this topic. Wish I had it with me so I could contribute. Left all my mahjong books and magazines in Japan cuz I had to come back in a rush :( Sucks.

    Nice read btw, thanks.

  5. I disagree about ex1, it’s a yaku , and I will call it.
    I will maintain my conservativeness, if anyone riichis after that, I can still defend though

    1. I’m pretty sure 80% of the #osamuko channel and 100% of the staff do not approve of your judgment on the situation. You drop to a 1000 point hand, with an infinitesimal chance to even get a dora. Your hand only has one two-sided wait, and no way to call red fives or the dora in hand. I’ll go a step further in this example. You are 3-shanten even if you do call it. Therefore, building a quiet hand slowly is the better option, as soon as risk comes, bail by dropping the chun pair. Or set, if you get it later. Please join the channel and we can discuss this further.

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