Disconnects: starting on Tenhou

The thing I hated the most when playing on Tenhou was how frequently new players would disconnect the moment they lose. This gives the player after the dc-ed player plenty of undefended Chi melds, as all of the dc-ed players' discards are automatic. It's something that simply can't happen in real life. Disconnects are more common by 新人 (level 0) players, but can be by anyone. The most annoying disconnect is on the first turn of the first game -.- like they saw their starting hand and just gave up...

Since I couldn't do anything about it, I tried my best to take advantage of the disconnects.

Hooray!! I'm directly after the dc-ed player~~~

1. Renchan is to your advantage. Since you have fewer connected players fighting for the win, there's a higher chance you can stay as the dealer and exploit the x1.5 dealer score bonus.

4 renchans! May the flow be with you~

2. End fast if you're winning. Playing against disconnected players can be unpredictable, as your still-connected opponents can take advantage of the dc-ed players just as you can. The Buttobi rule (game ends when player <0 points) can be used to kill off the dc-ed players.

Just 10 points away from dying!

3. Defend against remaining connected players, exploit the dc-ed ones. You can expect the dc-ed players auto-discards to feed into your winning hand, while the connected players defend against your riichi and tenpai.
4. Do not fear 4-6, fear honours. Waiting on 4-6 tiles is slightly more feasible since the discards are more random. However, honours get discarded less frequently as they just stay in the dc-ed players hand(s).
5. Riichi more! Since you're fighting fewer connected players, the risk of losing your riichi stick to another player's win is lesser. Also, you worry less about defending unless any of the remaining opponents still have a fighting chance.

5th turn Riichi during a double disconnect... Guess I'm just left with one opponent to trash......

6. Mangan! Haneman!! Build bigger hands if you can keep up with remaining opponents, though stay realistic based on opponent discards and don't be too greedy.

河底 is also more common since the disconnected players aren't defending

Learning Resources

I have used many different resources I picked up around the web, with my favourite being the Mahjong wiki at arcturus.su,

Personal resources:

• Excel sheets I created for learning (readme)
• Basic yaku test
• Complex wait test, basic waits included
• Score count table (instructions aren't clear yet but you can ask me)
• All Chinitsu possibilities test (currently not published)

Other helpful resources to check out:

• Japanese Mahjong overview at ofb.net
• There were many English terms which I found helpful, but got laughed at for using by my Chinese/Japanese-speaking friends...
• Mahjong Hand Score practice programs
• They have 3 different programs: fu practice, han practice and hand score evaluation.
• Satoshi Horiguchi's mahjong apps for iOS
• Required Mahjong Tiles i.e. wait determination for chinitsu and honitsu hands
• Mahjong Calculation Trainer i.e. score determination for winning hands
• Links at SG Riichi Mahjong learner's corner
• Particularly the Yaku Quiz
• and the Scoring Quiz
• I read through Daina Chiba's Riichi mahjong guide,
• It's a very detailed guide on improving tile efficiency, which you can also get a feel of by practicing and analysing many of your own games
• Take what is written with a pinch of salt. There is never only one way to play mahjong. Adapting to the playing style of your opponents is just as crucial!
• Osamuko.com
• I haven't checked osamuko's blog out that much to be honest, but I particularly liked his post on whether to go Kokushi Musou, as shared by my sg club.
• Akagi anime and manga. Saki is also pretty good, but I cannot stand the Yuri scenes.

Computing all Chinitsu possibilities

Chinitsu/Chiniisou (清一色 or one suit flush) is one of the most difficult hands to play in Japanese Mahjong because there are so many waits, it is easy to enter Furiten. Recognizing the best discard and multiple waits is a difficult but important skill to acquire.

A good start is to use the wait test from the Sample Pro Test by Reach Majong NY. There are 20 different hands of Chinitsu and Honitsu, mostly with multiple waits.

Just how many hands are there for each number of waits? This was a question that bogged me forever when I used to play Chinese mahjong, and even more so after playing Japanese mahjong.

I computed every possibility with a Python script backwards (building the hand from 4 melds (123/111) and 1 pair, then eliminating duplicates). This built every possible 14-tile mahjong hand.

There are exactly 13,259 possible 14-tile winning mahjong hands for Chinitsu.

Next, I wrote another script to compute every 13-tile hand in Tenpai (I removed 1 tile each from every 14-tile possibility and removed duplicates, then I attached the solution to every 13-tile hand).

The results were...

a total of 40,070 possible 13-tile hands in Tenpai. The table below depicts how many possibilities are there depending on the number of waits.

No. of waits	No. of possibilities
9	1
8	16
7	79
6	392
5	1335
4	2948
3	6739
2	14493
1	14067

There is 1 possibility for a 9-sided wait (the nine gates yakuman hand), and 16 possible 8-sided waits, all of which had a form of Happoubijin. You can see the 16 possibilities in a wiki sandbox I wrote for arcturus.su.

Learning about machi (wait patterns) and complex wait patterns helps a lot in seeing Chinitsu wait possibilities.

I am choosing to keep my computing output file private for the time being for academic purposes (as I noticed it was a university extra-credit question). You can email me if you want to see it, I might publish it at a later date.

How I started: adapting from app Mahjong to real-life Mahjong

I looked up a Japanese Mahjong app to start experiencing and choosing an ideal discard. I used an English app, Mahjong Demon Lite, instead of the Chinese/Japanese ones commonly used in my country, Singapore. I found this worked very well for me as a new player getting a feel of the game, but it might not for everyone, so I'll detail its pros and cons.

Pros

1. There was no time limit as it was against Computer AI, so you can think for a long time on which is the best discard that maximizes tile efficiency.
2. The absence of a time limit also helps you decide whether to open your hand with Chi/Pon/Kan, or keep it closed. This is important in deciding the direction of your hand.
3. There are helpful star-indicators for which tile is the dora, your round and seat wind, and the yakuhai. This feature can be toggled on and off.
4. The discards were not sorted properly in 6-tile rows, which gets confusing when you switch to real-life playing.
5. The app shows you every possible discard when you are in Tenpai and about to declare Riichi. This helps new players learn the many different directions a hand can go to depending on the discard (e.g. whether to choose a more efficient multiple wait, or a different single/shanpon etc wait based on discards or what you anticipate your opponents' hands to be)

Cons

1. Computer AIs are not a realistic depiction of players who go against conventional plays of maximizing tile efficiency. When you gain experience, I would recommend playing against real players on Tenhou.
2. As with most apps, there will be an option for you to Chi/Pon/Kan/Ron etc. This makes it hard to adapt to real life playing where there isn't that indicator.
3. Showing you every possible discard at Tenpai is a learning handicap. Recognizing these possibilities in real-life is important.

It was a fairly unsystematic style of learning. I gradually supplemented it with more knowledge of the game.

First, knowing your yaku. See ofb or wikipedia. I skipped yakuman hands but went back to it later.

• Supplementary readings: arc.su yaku compatibility

Second, understanding fu count to maximize small yaku hands, or choosing to deconstruct a large yaku hand when defending against opponents and still maximizing score.

Third, understanding wait patterns, both simple and complex.

• Having a good multiple-wait is helpful during Riichi, but even a simple wait 

Fourth, maximizing tile efficiency, while remaining discrete.

Fifth, when to Riichi or not to Riichi. (beginners generally Riichi immediately on Tenpai)

• Do you want to build your hand further? Is it more important to win early?
• Is it dangerous to Riichi? Will you just be feeding your Riichi stick to your opponent?

Sixth, playing with a tenacity to gamble. Know when to switch between Offense and Defense.

Seventh, manipulating your opponents through discard patterns.

And finally, reading your opponents, through discards and reactions, but never over-read.

First post!

Hello,

I'm just someone who recently started playing Riichi Mahjong a couple months ago at the Singapore Riichi Mahjong club and on Tenhou.

The way I play Riichi Mahjong is largely influenced from the 2 years I spent playing competitive Hearthstone (though I've since quit Hearthstone). Some of the principles I took from Hearthstone were to understand the meta, your opponents' "class" or playing style, and to stay unconventional so that the opponent cannot perfectly predict your cards, while optimizing efficiency and milking value in every one of your turns.

I used to play a bit of Chinese Mahjong, but never quite as competitively as how I'm currently playing and learning Japanese Mahjong.

This blog is to log the notes from my learning journey. It's not easy playing Mahjong in a male-dominated club, and I have a stubbornly perfectionist personality so I'm irked by every mistake I make, but I'm happy to strengthen my new skill and learn from others.

そろそろ、始めましょうか

Charmaine