2026 Sportsbook Fairness Report

Methodology

We calculated the implied overround (total implied probability minus 100%) for every two-way market across all sportsbooks in our data feed over a rolling 90-day window. The overround is the vig — the margin the sportsbook charges on each market.

Markets analyzed: moneylines, spreads, totals, and player props across NFL, NBA, MLB, NHL, NCAAF, NCAAB, MMA, and tennis. Only markets with both sides priced were included; removed or suspended markets were excluded.

All data sourced from real-time OddsBlaze feeds. For full details on our data pipeline, see Data Sources.

Average vig by sportsbook

The table below shows the average overround across all market types for each sportsbook in our data. Lower is better — a lower overround means fairer prices for bettors.

Data represents averages across all market types. Individual market types vary significantly (see below). Values are illustrative based on our data patterns — check the live feed for current pricing.

Vig by market type

Not all markets are priced equally. Spreads and totals tend to carry the standard -110/-110 vig (~4.5%), while moneylines on lopsided matchups and player props carry significantly more.

Player props consistently carry the highest margins — 30-50% more vig than main markets at the same book. This is because prop markets have less betting volume, less sharp action, and more model uncertainty.

Fairness by sport

Market efficiency varies by sport. Higher-volume sports (NFL, NBA) tend to have tighter lines and lower vig, while lower-volume sports carry more margin.

Lower efficiency = more +EV opportunities for informed bettors, but also higher risk of model error. MMA and college sports tend to have the most mispriced lines.

Props vs. main markets

Across all sportsbooks and sports, player props carry a vig premium of approximately 30-50% over main markets (spreads, moneylines, totals). This premium exists because:

• Less liquidity — lower betting volume means books can maintain wider spreads
• Model uncertainty — individual player outcomes are harder to model than team-level outcomes
• Information asymmetry — injury/lineup info can create one-sided action on props
• Recreational demand — casual bettors disproportionately bet props, tolerating worse odds

This is why DawBets applies an additional 50% Kelly reduction on player props — the higher vig means more estimation uncertainty, which warrants smaller bets.

Key takeaways for bettors

1. Line shop every bet. The spread between the sharpest book and the softest book on the same market is often 3-4 percentage points of vig. On a -110 line, that's the difference between a fair bet and throwing money away.
2. Be extra careful with props. The vig premium on props means you need a bigger edge to overcome the margin. Don't bet a prop just because it "feels right" — verify it's actually +EV against a fair price.
3. Sharp books set fair prices. Pinnacle and Circa's lines are the closest proxy for true probability. Use their prices as your benchmark when evaluating any other book's odds.
4. Volume sports are more efficient. Finding value in NFL spreads is harder than finding value in MMA props — but the edges in NFL are more reliable because the market is better calibrated.
5. The vig is your real opponent. You're not trying to beat the sportsbook's predictions — you're trying to beat their margin. Every half-point of vig you avoid through line shopping goes directly to your bottom line.

Frequently asked questions