Getting Free

A prisoner is given 2 bowls, 100 red balls, and 100 white balls. The prisoner is told to put the balls into the bowls any way he wishes, as long as there’s at least 1 ball in each bowl and all 200 balls are used. The prison guard comes in and will reach into a random bowl and draws out a ball. If it is RED, the prisoner stays in prison for the rest of his life. If it is WHITE, he goes FREE.

How should the prisoner arrange the 200 balls so that the prisoner has the greatest possibility of going free?

(Source: Adapted from Eric Saltsman)