  Dreidel is a popular game played during the festival of Chanukah. Players
start with an equal number of tokens, donate one token each to a common pot,
and take turns spinning a four-sided top, called the dreidel. Depending on the
side showing up, the spinner takes all the tokens in the pot, takes half the
tokens in the pot, gives a token to the pot, or does nothing. Whenever the pot
goes empty, everyone donates a token to the pot. The game continues till all
players, except one, go broke.
  We prove that the expected length of a game of dreidel is at most quadratic
in the number of tokens, irrespective of the number of players. This proves a
conjecture of Doron Zeilberger.
