"Mahjong Ukeire Trainer" is a free browser-based training app for building tile efficiency (the underlying skill behind nanikiru/discard decisions). It randomly generates hands within your chosen shanten and ukeire range, and you answer the actual ukeire count as a number — repeated practice that sharpens your tile-efficiency judgment. No registration, completely free. Add it to your smartphone's home screen to use it like a native app (PWA support). A nanikiru problem asks which tile to discard, while this app asks you to answer the exact ukeire count of the current hand as a number. It directly trains the ability to count ukeire accurately — the foundation that discard decisions are built on.
How to use
Open "Settings ▼" at the top of the screen and set the shanten level, ukeire range, and Full Flush mode you want to practice.
Once you're done, a problem matching your conditions is generated automatically.
Check the 13 tiles shown, then calculate the ukeire count needed to reach tenpai.
Enter the number you calculated using the calculator at the bottom of the screen.
Press the "Answer" button to check your result.
If correct: The "Ukeire" tab becomes active so you can check the accepting tiles. Press "Next" to move to a new problem.
If incorrect: A message appears and you can try again.
If you're not sure of the answer, press "Give up" to reveal the correct count and the list of accepting tiles.
Glossary
What is ukeire?
The total number of remaining tiles, across all useful tile types, that would advance the current hand's shanten by one (bring it closer to tenpai). It's the most basic measure for tile efficiency and discard decisions.
What is shanten?
A number showing how many more draws/exchanges are needed to reach tenpai. 0 = tenpai, 1 = 1-shanten, 2 = 2-shanten, 3 = 3-shanten. Known in English simply as shanten.
What is tile efficiency?
The approach of choosing discards that keep your hand's ukeire count as high as possible. It's the foundational skill behind nanikiru (discard) problems.
What is Full Flush (chinitsu) mode?
A restriction where the hand is built from only one suit — characters, circles, or bamboo. Counting ukeire becomes more complex, making it suited for advanced practice.