Yaku, Hai!: Riichi (& Ippatsu & Daburu Riichi)

In order to be able to build the best hands, you need to know both how to plan out your play with a hand, and how to execute that plan. This is the essence of hand development: taking that group of 13 useless tiles you start with, and using them to build a tenpai that wins you the game. In riichi, you are constantly confronted with choices like “Do I open my hand?”, “Do I just try to get to tenpai quickly, or am I okay with a slower, more valuable hand?”, and the ever-important “Do I fold?” The yaku are basically your toolbox of techniques to build hands, so understanding each of them is critical (especially in games where they contribute more to scoring, like when playing without open tanyao or red fives).

This is the first article in Yaku, Hai!, a new series of articles which  go into detail on each of the yaku in turn, explaining the rules surrounding them, when you would use them, and the nuances which may not be apparent at first glance. This first article covers the single most important yaku: the titular riichi. We’ll also cover riichi’s brother double riichi and cousin ippatsu, since their the strategy is simply a part of riichi’s.

Riichi is simple on the surface: stay closed, get tenpai, declare riichi, profit! But both the rules and strategies are very complex, making it one of the most difficult yaku to master. Riichi is one of the best reasons to stay closed until you hit tenpai, but that’s not all. There is an incredible amount of strategy that goes into the decision of when to riichi or not, and there is far, far more than one article’s worth to say about it.


Identifying Dangerous Suji

Suji are a popular defense strategy; so popular, in fact, that suji traps are an effective anti-defense. We would like to increase the yomi level and create an anti-anti-defense by identifying when suji traps are likely. Are there situations in which suji are more dangerous? Are they really traps, or are they just incidental discards?

Prominent authors actually disagree on this. Some claim that suji discarded after riichi are more dangerous, while others claim that suji discarded before riichi are more dangerous. The general agreement is that the tile discarded immediately upon declaring riichi is dangerous.

Who’s right? Do you think there’s a difference? Using the Tenhou game logs database, we can examine riichi hands and their discards to finally answer this question.


Mahjong Keypoints: How to become the strongest, 1

Horiuchi AKA HoriiLast year I bought a bunch of Kindai Mahjong magazines and read through most of them. I skipped most of the manga and concentrated on the mahjong articles (yes, I am a bitter man, and you can sue me later). In one of my editions of Kindai Mahjong Original, Houou (Phoenix Rank) of the 27th Hououisen, and Fourth Dan from the Japanese Professional League of Mahjong, Horiuchi Masahito, who is known to have a strong background of digital mahjong and a steady win record thanks to his defensive technique, has written a few articles about mahjong. This is probably the only translation into English of something written by Horiuchi. Those who followed him last year during the live edition of Hououisen broadcasted in NicoNico don’t need an introduction for this person.


Basic Defense Techniques in Mahjong

Hi, tenpaiman here (aka TMN or TemporaryMobileName or whatever else I happen to prefer to be called on any given day). Today I decided to do a translation of a mahjong article by totsugeki touhoku [とつげき東北], author of the famous Kagaku Suru Ma-jan series of books on digital playing and statistics-based theory of mahjong, discussing defense, betaori, and all that important stuff. As a preliminary to this article, you should read up on suji and kabe, which is discussed frequently in this article and forms the basis of most defense techniques in mahjong. You can do so here.


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.


Pechorin Style Doctrine

Do you ever feel like Tenhou is designed just to hold you back and that this game sucks, you have bad luck, you must be weak and you will never progress to the next dan (or kyuu) level? Then there is something wrong with your soul. You should read this.

I found this amusing post in Pechorin’s blog some time back, and even puyo posted a portion on his. I have been wanting to translate it for a while. These “commandments” are great for self encouragement and reassurance. Certainly fitting for pechorin (I recommend you follow him on twitter if you can read what he says). Let’s rejoice in wisdom.