Roulette

Roulette is a Bonus Challenge that involves luck in Super Mario World 2: Yoshi's Island, its remake for the Game Boy Advance, Yoshi's Island: Super Mario Advance 3, and its sequel, Yoshi's Island DS. Players place a bet on how many lives they wager on the middle of the first circle, and then the two circles have a light that will rotate. One of the circles counts as the equation, which will either be addition or multiplication, while the other one contains numbers ranging from 0-3. Players get the set number of lives depending on the equation they land on.

For example, if players bet fifteen lives, and the two circles land on X and the "3", they get 45 extra lives (15 x 3 =  45), which are displayed on the middle of the second circle. This gives the player 30 extra lives when the 15 lives entered is taken into consideration. Or if they bet ninety nine lives, and the circles land on "X" and the "3", the player gets 297 extra lives (99 x  3 = 297). Of course, anything multiplied by zero equals zero, and the Bonus Challenge will end if that happens. Fortunately, if one of the circles lands on a +, no lives will ever be lost. Up to 297 lives can be earned at one time, because they can only bet up to 99 lives. If the player has more than 99 lives, they can only bet 99 and can't bet any more than 99 lives. The player cannot bet on their last life.

Based on the numbers on the two roulettes, a probabilistic analysis shows that it is optimal to bet as few lives as possible each time this challenge is played.