o The "1-4-7 rule" is a good playing strategy (for all forms of Mah-Jongg except American (style similar to NMJL) in which there are no "chows"). If the player to your right discards a 4, and you don't have another of those to discard, you /might/ be all right if you discard a 1 or a 7.

The general strategy is to keep removing matching tiles so that each removal opens up more possibilities for future tile matching. If you have a pair that does not open anything, leave it until you need it. Don't forget that you should open up new tiles with every matched pair.