You're right if you only have one coin flip. But, this assumes a series of flips. The way I understand the Kelly Criterion it is it's similar to a fancy Marti

You're right if you only have one coin flip. But, this assumes a series of flips. The way I understand the Kelly Criterion it is it's similar to a fancy Martingale. It's statistically inevitable that X number of coin flips will go against you. So, the smaller % of your capital at risk, the less your risk of ruin. And, if you have an edge in the coin flip, the more flips you get, the better you'll perform in the long run. But, it's not that great of a proxy for real life as explained by other commenters in this thread.