THE GAME BEGINS IN THE MIDDLE (Article 135)

Commentary: American mah jongg is a game played in two phases, the first phase of the game consists of dealing the tiles and completing the Charleston. After the Charleston, East discards the first tile to start the second phase of the game when players pick one tile at a time, in turn. This is when the game actually starts.

Question from a player:  What signifies the start of a game?

Answer from the NMJL:  The game begins with East discarding an unwanted tile after the Charleston. This tile is discarded face up, calling it by name.

Source:  Mah Jongg Made Easy (2024 page 14)