Professional bettors and quants utilize the Kelly Criterion to optimize their bankroll management by determining the most advantageous stake size for each wager based on their perceived edge or probability of winning. By calculating the optimal bet size as a fraction of their total bankroll, they aim to maximize long-term growth while minimizing the risk of ruin. Many professionals apply the Kelly Criterion in combination with sophisticated statistical models and data analytics to derive accurate probability estimates for various outcomes, allowing them to make more informed betting decisions.