Before play begins, each player's seat determines their Wind position for the hand — East deals, and South, West, and North follow in order.
Most groups determine starting seats with a dice roll or by drawing Wind tiles face-down, then keep a Wind chart (or rack markers) to track how the East position rotates from hand to hand. Whoever sits East for a given hand deals and leads play.
Example
If you draw the East Wind tile before the first hand, you deal first, roll the dice to break the wall, and are dealt an extra 14th tile to start.