Probability of marbles

You have 50 red marbles, 50 blue marbles, and 2 large jars. The game is as follows: after all the marbles are placed into the 2 jars, you will pick a jar at random, and then a marble at random out of the jar. Your goal is to try to maximize the chances that you select a red marble. You are free to allocate the marbles however you want (including all 100 marbles into one jar, and none into the other), but all 100 marbles must be in either one jar or the other. How do you allocate the marbles, and what are the exact odds of getting a red marble using this scheme?