The Yankees play the Dodgers in the World Series.
The First team to win four games wins the Series.
You have $100 to bet on the Series, and you wish to bet on the Yankees winning the Series.
You wish to end up with a profit of $100 if the Yankees win the Series and you wish to limit your loss to $100 if they lose the Series.
However, you are only allowed to place bets (at even money) on individual games. That is, you can only bet on one game at a time and your betting opponent will match your bet with the same amount of money.
Carefully choose how much to bet on each game, to achieve your objective.