Intermediate · 4 practice decisions
Spot exchanges—and judge their timing
Evaluate what you give up as well as what the exchange brings in.
Check before you discard
On your turn after drawing or claiming, look for exposed jokers you can redeem before discarding. A surplus natural can become a useful joker even if that natural is not part of your target. Check the whole table, including your own exposures, and check again after an exchange.
Protect mandatory naturals
A joker cannot fill a single or pair. Trading a tile from a required pair for a joker can simply move the gap to somewhere harder to repair. In eligible groups of three or more, there is no rule requiring naturals to outnumber jokers; a group held concealed until Mahjong can consist entirely of jokers.
A blank preserves a future choice
Blanks are a house variation, not standard NMJL play. In the app, an enabled blank style allows a blank to recover an eligible settled natural discard at the configured time. The blank is spent in that exchange. Check the style’s timing; a live pending discard is not yet an eligible blank swap.
Do not spend flexibility automatically
Early in play, using a blank to fill a joker-eligible group can remove your ability to recover a required natural later. With a healthy wall, multiple targets, and no natural shortage, waiting can be sensible. It is not a rule to always wait: a scarce required natural, a strong immediate improvement, or a winning exchange can justify using it.
Compare the hand after the exchange
For a blank, ask which target the recovered tile supports and which future recovery you give up. For a joker, check whether releasing the natural opens a single or pair gap. Recognize a legal Mahjong created by the exchange before making another move.
Try a decision
It is your turn after drawing and before discarding. Another player has an exposed 5 Bam set containing a joker. Your 5 Bam is spare for your target and backups; a new joker fills one of your missing group tiles.
What is the useful action before discarding?
- Exchange the spare 5 Bam for the exposed joker
- Discard the 5 Bam because it is not in your target
Show the reasoning
Exchange the spare 5 Bam for the exposed joker. This converts a surplus tile into one that improves your hand. Check the resulting rack before choosing your discard.
Now change one condition. Your 5 Bam is now one of the two naturals in your required pair.
Try the paired situations in the app and see whether your reasoning changes.
Practise this