Mahjong School American · NMJL Standard
Member practice tool

Hand Diagnosis

Feed in your concealed tiles and the year's card. The engine tells you which lines are still alive, how far each is from complete, and what to throw next. Deterministic math, no guesswork, no AI.

Step 1 Pick your card, build your hand, mark any suits you have already exposed.

Tap a tile to add it to your concealed hand (up to 14). Tap a tile in your hand to remove it. Jokers are allowed.

Your concealed hand is empty.
Already exposed / blocked suits
0 tiles

Dead-hand check

Route analysis

Suggested discard

About Hand Diagnosis

Hand Diagnosis lets you drop in your concealed tiles and see which card lines are still alive, how far each is, and what to discard next.

It is a practice tool for working a hand against the structure of the card without guessing. Bring your own card for real lines; without it, the families shown are illustrative only.