If you are a Tenhou player, you should have known that there are 4 different rooms for 4 different levels: Ippan, Joukyuu, Tokujou, Houou. Before getting to the main parts of this article, let’s see what those 4 levels are about – those descriptions are from the famous Riichi Book I, by Daina Chiba.
1. 一般 (ippan; lower-level room)
This is the only room where you can play initially. Games in this room can sometimes be a bit random, even chaotic at times. Some of the players in this room probably do not understand the rules very well. You very rarely come across strong players here.
2. 上級 (joukyuu; upper-level room)
You can play here if (1) your rank is 1 級 or higher or (2) you buy a two-month membership.
Games in the joukyu room are more reasonable than those in the lower-level room, but you still see many players who do not defend at all, do meaningless dama / unreasonable riichi, and make serious mistakes in maximizing tile efficiency.
In my impression, games at EMA tournaments most resemble games in the ippan and joukyuu rooms.
3. 特上 (tokujou; advanced room)
Requirements to play in this room are pretty demanding. You have to have a 四段 or higher rank and a 1800 or higher R. The latter requirement is particularly difficult to satisfy for intermediate players. As I wrote above, achieving the rank of 四段 is not that difficult, but satisfying the R ≥ 1800 condition requires that you take mahjong rather seriously. Since weak players are shut out from the tokujou room, games in tokujou are qualitatively different from those in the joukyu and ippan rooms. Games in this room feel similar to those you’d experience at regular mahjong parlors in Japan.
4. 鳳凰 (houou; phoenix room)
This is the highest-level room in Tenhou. In order to play in this room, you have to have all of the following: (1) a 七段 or higher rank, (2) a 2000 or higher R, and (3) a paid membership. Satisfying the first two conditions can be really, really challenging. This is arguably one of the highest-level mahjong locales in the whole world.
The article is mainly for Joukyuu players – my suggestion on what they could do to achieve Tokujou level. Including players that have reached Tokujou but drop back easily. (And yeah, there’d be article(s) about Tokujou players. Probably not as good as this one.)