Sportsbooks Avoid Bets from Winners

Gamblers who manage to beat sportsbooks say they are often shut down when they succeed too much.

Dave Holmes, a sports bettor in Chicago, said that as he started to win more using a math-based wagering strategy, companies including BetMGM, ESPN Bet and Caesars began rejecting his bets.

It is not surprising that sportsbooks are limiting adverse selection. Limiting risk this way may or may not be fair, but it is profitable.

Is using data analytics for betting more like casinos banning blackjack players from counting cards or  more like day-traders developing sophisticated algorithms to arbitrage implied differences in security prices? Securities markets are positive-sum games and better analytics generate more informative price signals for many others to use. Gambling on sportsbooks, like gambling at casinos, is a zero-sum game and "the house" only earns money because the odds are in their favor. Eliminating that edge could make the whole enterprise nonviable. Or it could just mean that the house must do better at developing mechanisms that balance the odds.