The Difference Between Optimizing for an Individual Hand and Playing Optimal

Poker is a very high variance game. You can play poker for a full year and make money and actually be a losing player because you just got lucky. If you want to evaluate how good your bot is in a tournament, you have to play whole tournaments to get one sample. And so you might have to play like a hundred or a thousand tournaments in order to get a statistically significant measure of whether your bot is actually good.