Question: If a player knows they have a dead hand, should they announce it and stop playing?

Answer: A player should not call their hand dead, even if their hand is no longer viable. Instead, they should continue to play defensively doing whatever is necessary to throw only safe tiles and/or Jokers.

A hand is only declared dead by another player, and then the player with the dead hand stops playing. Also refer to ID151-Calling a Player’s Hand Dead-Strategy or Not?

Source:  National Mah Jongg League Bulletin 2021 (updated 2/2021)