There are just four kinds of bets. There are good bets, bad bets, bets that you win, and bets that you lose. Winning a bad bet can be the most dangerous outcome of all, because a success of that kind can encourage you to take more bad bets in the future, when the odds will be running against you. You can also lose a good bet no matter how sound the underlying proposition, but if you keep placing good bets, over time, the law of averages will be working for you.