Betting 101
What Is a Spread?
The point spread is the expected margin of victory set by oddsmakers. If the Kansas City Chiefs are -4.5 against the Las Vegas Raiders, Kansas City must win by 5 or more points for a spread bet on them to pay out. Conversely, a bet on the Raiders "covers" if they lose by fewer than 5 points or win outright. The half-point eliminates the possibility of a push (tie against the spread).
What Is a Moneyline?
A moneyline bet is simply picking who wins the game, with no spread involved. Odds are expressed relative to $100: a -150 favorite requires a $150 wager to win $100, while a +130 underdog returns $130 on a $100 bet. Moneylines are popular when you have strong conviction on the winner but don't want to worry about the margin.
What Are Totals (Over/Under)?
A totals bet is a wager on whether the combined score of both teams will be over or under a number set by oddsmakers. If the total for a game is set at 47.5, you bet Over if you expect 48 or more combined points, or Under if you expect 47 or fewer. Totals are independent of who wins the game.
What Does ATS Mean?
ATS stands for "Against The Spread." It measures how often a team (or a model's picks) covers the point spread. An observed ATS win rate describes that sample; it does not predict future results. The breakeven ATS rate at -110 odds is about 52.4%, excluding pushes.
What Does -110 Mean?
The number -110 is the standard "juice" or "vig" (vigorish) on spread and totals bets. It means you must risk $110 to win $100. Both sides of a spread bet are typically priced at -110, which gives the sportsbook a built-in margin of about 4.5%. At -110, the break-even win rate is about 52.4%, excluding pushes.
Breakeven Calculator
Enter American odds to see the implied probability you need to break even.
At -110, you need to win 52.4% of bets to break even. At -105, only 51.2%.
Putting It All Together
Smart bettors compare the implied probability from the odds against their own estimated probability. When your model says a team has a 60% chance of covering but the odds imply only 52%, the difference depends on your estimate being accurate. Shark Snip lets you backtest models and compare their predictions with observed results.