Bookies and sportsbooks have various ways to detect if you are arbing. One common method is monitoring the starting price of a horse or a team in a competition. If your bets consistently exceed the starting price, it raises suspicion of arbing. Another way bookies detect arbing is through the bettor’s consistent profitability over a long period of time. Winning every bet is mathematically impossible, so it is natural for bookies to suspect foul play.