Question: My instructor taught me to pick and rack my tile before discarding, but I’ve noticed many experienced players skip racking altogether. What’s the official rule on this

Answer: While racking your tile before discarding is not mandatory, it is a recommended practice because it effectively closes the window of opportunity for another player to call the previously discarded tile.

Important Exception:
If a player wants to perform a joker exchange with a tile already in their rack, the tile just picked must be racked first. Failing to do so means the player may temporarily have fewer than 13 tiles on their rack, which would make their hand subject to being declared dead.  Mah Jongg Made Easy 2024, pg. 16, #1)

Courtesy Matters:
Racking also creates a natural pause, just a beat or two, that allows other players, especially beginners, a chance to consider the last discard. This is particularly helpful at mixed-skill tables. Fast-paced players often pick and discard in one motion, but a brief pause can make the game more enjoyable and inclusive for all.

Source: Mah Jongg Made Easy 2024, pg. 17, #8