For the last few months I’ve been focused on building RiichiCam, a free web app (works on any device) that makes scoring hands much easier and faster than using a scoring sheet, especially for players that are newer to playing over the board. You take a photo of your winning hand and the app gives you a full yaku, fu, and payments breakdown.

My first attempt at the vision model only used open-source tile images, plus a couple hundred of my own to fill in the gaps. Its accuracy was spotty at best, and it could really only support one tileset. After deciding to add more variety by rendering thousands of synthetic images for model training, accuracy improved to practically perfect in real-world conditions under a variety of tileset styles. I’ve had a few local clubs test it out and have heard great things.

Moving model inference to on-device instead of routing through a server also cut the time from taking a picture to being able to score the hand down to about 200 milliseconds, which I’m super stoked about.

Would love to hear any suggestions you guys might have to make the app more convenient to use! The scanning feature is the most complex part of the app so I want to make sure it’s easy to understand and fast.

If you’re interested, you can check it out at riichicam.com!

(Disclaimer: the majority of the implementation work on this project was done with generative AI, but the product design and engineering decisions are mine.)

Im new and i've been trying to win the mahjong cups at Like a Dragon. I had this hand with a triplet and a pair but i don't know why i didn't win since my oponent dropped that last tile for my hand.

What im doing wrong?

I’ve made quite a few browser-based board game sites, but this was easily the most complicated one so far.

My wife loves Riichi Mahjong, so I spent the last few weeks diving deep into the game while building this, constantly asking her questions and learning everything from chi, pon, and kan to yaku, furiten, dora, and scoring.

I tried to keep the interface simple: open the site and start playing immediately, either against the AI or with friends in a private room.

I’ve tested the rules as carefully as I can, but Riichi has a ridiculous number of edge cases. I’d really appreciate feedback from experienced players, especially if you spot any rule, scoring, or UI issues.

RiichiMahjong.com

AI disclosure: AI tools were used to assist with some visual assets and the development of the game.

This was my first time ever playing it. And it was amazinggg, haha. I learned it that day, hopefully will get more chances in the future. Do like mahjong? How long have you been playing it? Tell me about you craziest times or wins u had !! I am curious.

Wacky Riichi variants y'all enjoy? More than Sanma, Aotenjo, Yami Mahjong, Washizu... Bonus if you can play it with a standard play set

I have the two han minimum rule on, as you can see on the second photo but he still won some how? It was godly kazuya he's sitting east and I believe the wind indicator was still east. Sorry if I got any of the terminology wrong I just started learning two days ago.

The Dora is 6 bamboo but he didn't have any because I had them all (I was going to score so many points 😭)