Moneyline odds explained: implied probability and finding an edge
Every moneyline price is a hidden percentage. Once you can read it, you can tell in seconds whether a bet is worth a look or just a story.
From odds to break-even
Underdog (+odds): break-even = 100 ÷ (odds + 100). A +190 dog: 100 ÷ 290 = 34.5%.
Favorite (−odds): break-even = odds ÷ (odds + 100). A −150 favorite: 150 ÷ 250 = 60%.
What is an edge?
Your edge is the chance a team actually wins minus the break-even rate. If a model gives that +190 underdog a 39% chance, the edge is 39% − 34.5% = +4.5%. If the model says 30%, the price already took the value and the edge is negative.
Don’t forget the vig
Add up both sides’ break-even rates and you’ll get more than 100%. The extra is the sportsbook’s cut. A standard −110 spread bet needs 52.4% to break even, not 50%. Sharp Sully includes the vig in every edge it shows.
What history says about favorites and dogs
| Since 1999 | Rate |
|---|---|
| Favorites covering the spread | 48.7% |
| Underdogs of 7+ points winning outright | 20% |
| Underdogs of 10+ points winning outright | 15% |
| Home teams winning | 56% |
Source: nflverse game results and closing lines, 1999–2025 regular and postseason games. Spread figures exclude pushes and pick’ems.
See this week’s edges on the free cheat sheet →Common questions
How do you calculate implied probability from moneyline odds?
For plus odds, divide 100 by (odds + 100). For minus odds, divide the odds by (odds + 100). +190 is 34.5%; −150 is 60%.
What does edge mean in sports betting?
Edge is your estimated chance of winning minus the break-even rate the odds imply. A positive edge means the price is better than the true chance.
What win rate do you need at −110?
About 52.4%.