What is the Kelly Criterion?

The Kelly Criterion is a mathematical formula for calculating optimal bet size based on your estimated edge. The formula: f = (bp - q) / b, where b = decimal odds minus 1, p = your estimated win probability, and q = 1 - p. Many bettors use "half Kelly" for safety, as the full formula can call for very large bets. It requires accurately estimating your true win probability.