When betting on sports, a good strategy is to make your bets based on the numbers rather than the teams you like or your gut instinct. The goal is to produce positive expected value (EV, or profit) over time. To find value, look for a discrepancy between your estimate of the probability that a bet will win and the odds on it. The bigger the difference, the better.

Odds are a representation of the payout amount based on a bet’s probability, so a bet on a coin toss would have odds of 50/50 or even money (+100) for heads or tails. Bets can be made on individual events, spreads, over/unders, teasers, and parlays. Each bet type has its own risk/reward profile, and the key to success is thorough research. This includes studying team statistics, player performance, injuries, and historical matchups. Thoroughly tracking your wins and losses is also critical to refining your strategy.

A general rule of thumb is that each bet should represent one to two percent of your total bankroll. It is possible to reduce this to 0.5 percent if you are very confident in a bet, but be careful not to increase it to four percent or higher. Some bettors create multi-tiered bankrolls with different allocations for different kinds of bets. These allow bettors to focus on the most profitable bets while limiting exposure. Others may specialize in a specific event or sport and create sub-bankrolls tailored to those events.