Props (Proposition Bets)

Props (proposition bets) are wagers on specific events within a game, separate from the final outcome. Instead of betting who wins, you bet whether Patrick Mahomes throws over 2.5 touchdowns or if there's a safety in the first half.

Types of Props

Player props dominate volume. Exotic props are entertainment, not investment.

Props vs Main Markets

Props are less efficient but also less liquid and higher-vig.

Finding Prop Edge

Props can offer value because:

Less sharp attention. Main markets are picked clean; props may be overlooked.

Model-able situations. If you model receiving yards well, you might spot mispriced lines.

Correlated info. Injury or weather affects props before main lines adjust.

Book laziness. Some books copy lines rather than model independently.

The Prop Trap

Props also have pitfalls:

High vig. 15-20% combined hold on some props. Edges must be huge.

Low limits. Even if you find edge, you can't bet significant size.

Correlation risk. Player props within games are correlated. Parlaying them compounds error.

Same-game parlays. Books heavily push SGPs because the math brutally favors the house.

Sharp Prop Strategy

Professionals approach props carefully:

1. Focus on low-vig markets. Some books offer -105/-105 on props.
2. Build specialized models. Deep knowledge in one area beats broad coverage.
3. Monitor injuries. Backup players get usage; starters' absence affects multiple props.
4. Track closing lines. CLV matters even on props.

Props on Prediction Markets

Kalshi offers prop-equivalent markets:

• Player milestone markets
• In-game event markets
• Quarter/half-specific outcomes

The exchange structure often provides better pricing than sportsbook props.

Related Terms

• Parlay — Often combined with props (dangerous)
• Vig — Higher on props than main markets
• Limit — Typically lower on props