Riichi Mahjong Score Trainer

[Jesper Sahu]

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You can also see a video of a strong player talking through his thoughts at this link.

This is a tile efficiency trainer for Japanese (Riichi) Mahjong. It could work for some other forms of Mahjong, but won't recognize any yaku/fan that aren't in Japanese Mahjong, so it will be somewhat inaccurate.

For every possible discard, the trainer will check how many tiles the resulting hand could draw to improve its shanten (distance from ready). If you discard a tile that isn't the best option, it will tell you the difference in efficiency. The drill completes when the hand reaches ready.

Note that playing simply for efficiency is not the optimal way to play Mahjong. It can make you easier to read. Defense is much more important. Going for high value hands often requires going against efficiency. There are many articles online that can elaborate on this. But, knowing how much efficiency you're giving up can help you better assess whether it's worth going for. This reddit comment has more info.

For example, 340m778s236677p55z. The order of the suits doesn't matter, and you can have as few or as many as you want. Any invalid characters will be ignored, so a string like "345 man 778 sou 236677 pin 55 honor" would also (coincidentally) work, as all the extra letters don't represent suits. If you provide a hand with fewer than 14 tiles, tiles will be added at random to fill it. A hand with more than 14 tiles will result in only the last 14 tiles appearing. A hand with more than 4 of a tile will only have 4 of that tile.

In the Defense Trainer, I've had a couple of times where I've discarded a tile that I thought was suji (e.g. 6s when the riichiing opponent had already discarded both the 3s and 9s) but wasn't, as well as a couple of times where I didn't discard a tile that I thought wasn't suji (e.g. 1m when nobody had discarded the 4m), but which I should have because they were. Am I misunderstanding suji, or is this a bug? If it's the former, is there documentation on what counts as suji and what doesn't?

For the former case, I assume either the 3s or the 9s was the riichi tile. Generally speaking, suji information from the riichi tile is considered less valuable; for the purposes of this trainer, the riichi tile should be ignored when determining suji by the standard "three away" method.

I think one-chance is when there's three copies of a tile out or in your hand leaving only one possible for an opponent to have. So if you have a 1 and you see three 2s out, you know the chances are way slimmer they have the 2 and you'd throw the 1 hoping for the best.

Select a player to be East seat - the other will be West. Each hand the players will switch. Shuffle a full set of tiles and each player draws 34 tiles into rows in front of them. A pair of tiles, one dora (face up) and one uradora is also set aside. From their own drawn tiles, players must create a 13 tile hand in tenpai worth at least mangan (this includes riichi as well as dora.) There are no round winds, only seat winds. Kans are not allowed. Furiten rules still apply. Players begin with a normal allotment of points

Winning hands must be mangan or better - 4 fan 30 fu and 3 fan 60 fu hands are rounded up. Riichi is counted as well as ippatsu (win on first deal) and houtei (win on last discard). A declared win that does not meet the minimum score is considered chombo.

Draw and discard as normal. At any time while discarding, if not furiten, a player may Reach. This ends phase 1 of the game and moves on to phase 2 below. If you do this and are not dealer, you become dealer next hand.

The non-reached player guesses 2 tiles. If either of those completes the hand, the hand ends as a draw, otherwise the reached player draws and discards 5 tiles, one at a time. If any tile completes their hand, they win. If there is no winning draw repeat the previous steps until the wall runs out, in which case the hand is a draw.

Mahjong is a tile-based game most similar to a cross between Gin Rummy and Poker. It was originally created in China, but the popularity spread quickly, and nearly every single area in Asia has its own variant.

This is an incredibly short read and should teach you just enough to be a threat to someone while playing in a video game version, such as in Yakuza. You shouldn't rely on this as there is a lot, lot more to learn, but this isn't bad for a fast method.

Yaku List

Yaku List Alt

Yaku For Beginners Images that list all the yaku in the game, for quick reference. For more infographics, check out the booru's guide tag. Where to play the game online? Mahjong Soul

A Chinese-made Riichi Mahjong game that came out for English and Japanese as well. The interface is fairly stylish, the music is pretty good, and it allows you to spam emotes from kawaii waifus and husbandos. There is a gacha game attached to it so you can change out the waifus and their outfits, but everything relating to Mahjong itself is free and is working fairly well. Recommended for beginners at the game, since the best way to learn mahjong is to just keep playing.

This is generally where most of the serious players tend to wind up. There is a "Tenhou English UI" extension that can be installed for Chrome and Firefox. The English UI only works for the HTML5 version of the game which can be found at tenhou.net/3/. A guide for the general interface and rules can be found here:

It has the same approach as Mahjong Soul, combining mahjong with gacha. But unlike majsoul, the game is far kinder when it comes to it's gacha system, with tons of free rolls (which you can use ro reroll for whoever strikes your fancy), cosmetics, and a mathematically higher chance of getting something useful. Sadly, it has no english translations as of this moment.

An up-and-coming riichi mahjong client (made by the japanese this time) with the same philosophy as Mahjong Soul: mahjong with gacha waifus. And has an English language option. Still has a fairly small playerbase thanks to mahjong soul sucking up most of the target audience, but it's steadily growing and you can help out with that. The gacha is a lot more forgiving, there's animated emotes and set phrases, and you can actually see the wall this time.

Official release of the Majsoul/Hime Killer. This time, every girl needs to be rolled and the only default is Azur Lane Girl. The downside: it's janky as fuck. No upsides. Everything's broken, as what would you expect of a cheap chinese knockoff of cheap chinese knockoffs.

An old client-based online app. It was free-to-play, but then turned into pay-to-play during an update and almost all of the playerbase dried up overnight. Only mentioning because the P2P version can still be found in a search for Mahjong. DO NOT RECOMMEND.

The most tryhard of all clients, it's the Japan Professional Mahjong League platform. You can regularly find pros playing in here. As f2p, you can only play 1 ranked tonpu each day, anything more needs a subscription. Friendlies are free. Clients looks like it comes (and it does) from 20 years ago. English guide on how to start playing here .

Autotable is a tabletop simulator for Riichi Mahjong. You have to do everything by yourself, calls, scoring, drawing tiles... If you have friends and voice chat it's a great experience. Features various playing (4p, 3p, custom dora, Washizu) modes and an abema-like spectator mode. An anon is hosting it for /mjg/ to use.

Do you want to stop being bad at mahjong? Read this. RB1 is essential mahjong reading. Teaches tile efficiency, defense strategies, yaku chasing and everything else to bring you to the level of an intermediate player.

I have not shilled this resource hard enough. This is an alternative to Riichi Book 1, if that book reads like runes to you. I'd actually recommend this more than riichi book 1, but anons in the thread seems to swear by RB1 so you be the judge and read the two. Still, for anyone still stuck at RB1 and can't finish it, this is the book for you. It's a pdf version of this site, and the lessons are neatly divided into three parts.

A book by Fukuchi Makoto and translated by a kind anon. The book is heavily focused on tile efficiency, with a highly digital (analytical) way of thinking. All of the later material about push-fold judgment and discard reading is based on good tile efficiency.

The three books aboves, as well as more strategy guides and resources, can be found in this section of Guides. You should definitely check out most of them to improve even more, or as alternatives if the two books above isn't enough for you.

The EMA is the official tournament rules for Riichi Mahjong in the Europe area. They also tend to be the most popular ruleset to reference when people translate the game due to various factors. The rules here are more focused on tournament play, and thus will skip over various rules that you may see in other games.

A simple app to help you work on your efficiency in discards. The app is simplistic and doesn't take a holistic view of the table. Rather, it merely measures how efficient your discard is by how many tiles it believes would improve your hand to tenpai, and nothing else. You have great efficiency if you can consistently score 95% or higher on this over several attempts.

This is a single-suit variant. This will give your brain a very intense workout. Definitely not recommended for beginners still learning the game, but included for advanced players looking to become better.

Blue button generates new hand and orange button shows answers. Top left determines number of tiles: either 7, 10, or 13. Below that is sorted or unsorted (sorted by default). Top right determines the suit (manzu by default)

Entirely in Japanese, but the blog has instructions. Taken from the pathofhouou blog: Hitori Mahjong Simulator is a useful tool for getting statistics about the expected value or speed of a hand. It has some limitations, for example not considering calls, but you can still get good stuff out of it.

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