Wall Game (Article ID 137)
Abstract: A wall game occurs when all tiles have been exhausted and no one has declared mah jongg. There are several theories as to why a wall game might occur. “Dogging” too early by beginner players and or “Dogging” at the appropriate time during a game can attribute to a wall game. Experienced players might experience more wall games by virtue of very defensive play.
Statement from a player: We cannot understand why we have so many wall games?
Answer from the NMJL: “There is no set rule for dogging. Discretion on the part of the player must be used. Discards and exposures must be taken into consideration. Also, the shorter the wall, the more reason for careful dogging. A player discards only tiles that are obviously not needed by any player. Very often a player will break up their own hand in order to discard safe tiles. It is important to remember while trying to complete your hand that it is just as important to prevent the other players from completing their hand.”
Source: National Mah Jongg League Q&A 1984 http://www.nationalmahjonggleague.org