Player props explained
What a player prop is, how overs and unders on a player's stats work, why props carry a bigger margin, and how to compare them.
A player prop is a bet on what one player does in a game, not on which team wins. Will a basketball player score more than 24.5 points? Will a quarterback throw for over 255.5 yards? Will a striker score at any time? The final score only matters as far as it shapes that player's numbers.
Overs and unders on a stat
Most player props work like a total, applied to one player's stat line. The sportsbook sets a number and you take a side:
- Over wins if the player records more than the line.
- Under wins if the player records fewer.
Say a player's points line is 24.5, with the over at -125 and the under at -105 (the American odds guide explains these prices):
| Points scored | Over 24.5 at -125 | Under 24.5 at -105 |
|---|---|---|
| 31 | Wins 80.00 on a 100 stake | Loses |
| 25 | Wins 80.00 on a 100 stake | Loses |
| 24 | Loses | Wins 95.24 on a 100 stake |
Half-point lines such as 24.5 can never push. On a whole-number line such as 6 rebounds, exactly 6 is a push and the stake comes back.
Common stat props include:
- Basketball: points, rebounds, assists, three-pointers made, or combinations such as points plus rebounds plus assists.
- American football: passing, rushing and receiving yards, receptions, touchdown passes.
- Baseball: a pitcher's strikeouts, a batter's hits or total bases.
- Hockey: shots on goal, points (goals plus assists), a goalie's saves.
- Football (soccer): shots, shots on target, tackles.
Yes-or-no props
Some props have no line, only an outcome: will the player score a touchdown, score a goal, or record a double-double (10 or more in two stats, such as points and rebounds)? Often only the "yes" side is offered. An anytime goalscorer price of +250 implies 100 ÷ 350 = 28.57%, and a 100 stake wins 250 if the player scores.
Milestone props are a close cousin: instead of over 24.5 points you might see "25+ points" as a yes-only bet. It is the same question as the over, sometimes at a different price, so it is worth comparing the two.
Why props carry a bigger margin
The main lines on a game attract a lot of money and a lot of attention, so sportsbooks price them tightly. Props are harder to price, there are hundreds of them per game, and each one is bet in smaller amounts. The result is a wider margin.
Take the points prop above. The over at -125 implies 125 ÷ 225 = 55.56%, and the under at -105 implies 105 ÷ 205 = 51.22%. Together they add up to 106.78%, an overround of 6.78%, which means the sportsbook expects to keep about 6.35% of the money staked. A main line priced -110 on both sides adds up to 104.76%: an overround of 4.76% and a margin of about 4.55%. What the vig is explains the arithmetic in full.
Finding the fair price of a prop
When both sides are offered, you can take the margin out. Scaling 55.56% and 51.22% back to 100% gives fair probabilities of 52.03% for the over and 47.97% for the under. That is fair odds of about -108 and +108, or 1.92 and 2.08 in decimal. Try it with the no-vig calculator:
Read as American odds: −110
Read as American odds: −110
Margin 4.8%: the prices add up to 104.8%.
| Outcome | Implied | Fair chance | Fair price |
|---|---|---|---|
| Outcome 1 | 52.4% | 50.0% | +1002.001/1 |
| Outcome 2 | 52.4% | 50.0% | +1002.001/1 |
The fair price spreads the margin across the outcomes in proportion to their implied probabilities.
A yes-only prop has no second side, so its margin cannot be removed this way. The best yardstick there is the same prop at other sportsbooks. The fair odds guide explains why fair prices are a useful reference.
Comparing props between sportsbooks
Sportsbooks disagree on props more than on main lines, because each sets its own numbers on a market with less money behind it. Compare two things:
- The line. For the over, a lower line is better at the same price. Over 23.5 points wins on 24 points; over 24.5 does not. For the under, a higher line is better. On a stat with small numbers, such as 4.5 assists, a single step in the line changes a lot.
- The price. On the same line, a 100 stake on over 24.5 wins 90.91 at -110 and 80.00 at -125.
When one sportsbook has a better line and another a better price, neither is automatically better: it depends on how often the player finishes exactly between the two lines. OddsKeepr shows each sportsbook's line and price side by side for the leagues where it lists props, and how to compare odds walks through the method.
Rules worth knowing
- Did not play. If the player takes no part, the prop is usually void. If they play even briefly, it usually stands, though pitcher props usually need the named pitcher to start: one who comes on in relief leaves the bet void. House rules set the exact test.
- Stat corrections. Leagues sometimes correct stats after a game. House rules say whether the sportsbook settles on the figures at the end of the game or waits for corrections.
- Combining props. Several props on the same game are often linked: a quarterback's passing yards and a teammate's receiving yards tend to rise together. Sportsbooks price such combinations as a same-game parlay, not as an ordinary parlay, and that price usually carries extra margin on top of each prop's own.
- Where props are allowed. Some places restrict props, for example many US states ban props on college players.
Props carry a bigger margin than the main lines, so on average they cost more. If you bet, set a limit you are comfortable with and check that the sportsbook is licensed where you are. If gambling stops feeling like entertainment, free and confidential help is listed for every country under where to get help.