Prop Bet (Proposition Bet)

Prop bets are wagers on outcomes that occur within a game or season but don't depend on the final result. The most common categories:

- Player props: "Will Patrick Mahomes throw for over 275.5 yards?" - Team props: "First team to score in the first half" - Event props: "Will there be a safety in the game?"

Props are higher-vig markets than game lines (typically 8-12% vs 4-5%) because: 1. Books have less data and more uncertainty 2. Volume per market is smaller 3. The "fair" price is harder to estimate

This is also why props can be the most valuable for sharp bettors: if you can model a specific player's performance better than the book, the wider vig can be overcome by a precise opinion.

For golf, props include things like "eagle in round" or "lowest round score." For NFL/NBA, anytime touchdown scorers, player point totals, and player-vs-player matchups are most common.

SportsBookISH tracks golf props (via the golfodds_props table) and is rolling out NFL/NBA player props in 2026.