What is Prop Bet?
A bet on a specific event inside a game — most often a player stat over/under, but also team props or game props.
Also known as: proposition bet, player prop
Player props (e.g. LeBron James over 25.5 points) are the fastest-growing market in US sports betting because they are skill-friendly: with the right data on usage, pace and defensive matchup, a model can find edges that the book has not fully priced. The downside is sharp limits — books cut winning prop bettors fast, so line shopping and rapid execution matter.
Example
Aaron Judge over 1.5 total bases at +120. He homers in the first inning — instant win.
Related terms
A single bet that combines two or more legs into one ticket — all legs must win for the parlay to pay.
Expected value (EV) is the average profit or loss a bet pays per dollar staked if you repeated it under the same odds and probability forever.
Comparing prices at multiple sportsbooks to bet the best available number on every play.
See prop bet applied to a real slate
NotaSportsGuru runs the math behind every published leg — Parlay of the Day, player props, match lines — with the model’s expected value and edge on every line.