Spread betting in the NBL (National Basketball League) requires a bettor to pick not just a winner but a margin of victory. A team listed at -5.5 must win by six or more points to cover, while the underdog at +5.5 can lose by five and still cash the ticket. Unlike football spreads, which cluster around key numbers like 3 and 7, basketball spreads are more fluid — half-point margins matter less structurally, but the faster pace and higher scoring mean leads can evaporate quickly, making late-game variance a constant factor.
The spreads market in the NBL tends to offer the most value when sharp information hasn't fully filtered into the lines — early-week openers, games involving teams on back-to-back travel legs, or matchups where key import players are questionable. Bettors should track lineup confirmations closely, as a single absence in an eight-man rotation can swing a line by four or more points. Vig on NBL spreads generally sits in the -110 range at competitive books, which is tighter than totals and significantly better than player props, where juice often balloons past -115. Comparing vig across books on these lines is one of the simplest ways to protect long-term margins.
Cross-Sport spreads Vig Comparison
NBL spreads averages 5.58% vig across 1 sportsbooks. Here's how that compares to other active sports:
| Sport | Avg Vig | vs NBL |
|---|---|---|
| NBL | 5.58% | — |
| NCAAF | 4.75% | 0.83% higher |
| AFL | 6.97% | 1.39% lower |
| MLB | 4.09% | 1.49% higher |
Vig Rankings
| # | Sportsbook | Vig | Grade | Events |
|---|---|---|---|---|
| 1 | BetRivers | 5.58% | C+ | 1 |
Frequently Asked Questions
Which sportsbook has the lowest NBL spreads vig?
BetRivers currently has the lowest vig at 5.58%, earning a grade of C+.
What is vig (vigorish) in sports betting?
Vig — short for vigorish, also called juice or overround — is the margin a sportsbook builds into its odds. It's the difference between the true probability of an outcome and what the odds imply. Lower vig means you keep more of your winnings on every bet. For example, a standard -110/-110 line has about 4.76% vig.
How often is this data updated?
We pull fresh odds from The Odds API three times per day — at 6:00 AM, 2:00 PM, and 10:00 PM UTC. Each snapshot captures the latest lines from every sportsbook that has posted odds. The timestamp at the top of the page shows the most recent refresh.
How is the vig grade calculated?
Each sportsbook is graded on a letter scale based on average vig: A+ (under 2%) is exceptional, A (2–3%) is excellent, B+ (3–4%) is above average, B (4–5%) is the industry standard, C (5–6%) is below average, and D (above 6%) indicates high-juice markets.
Why does lower vig matter for bettors?
Lower vig directly impacts your long-term returns. A bettor placing $1,000 per week at a book with 4% vig loses roughly $40/week to the house edge. At 2% vig, that drops to $20/week — a $1,040 difference over a year. For serious bettors, shopping for lower vig is one of the most reliable ways to improve profitability.
What sportsbooks do you track?
We track both regulated US sportsbooks (DraftKings, FanDuel, BetMGM, Caesars) and offshore books (Bovada, BetOnline, MyBookie, BetUS, LowVig.ag, BetAnySports). Data comes from The Odds API, which aggregates real-time lines from licensed sources.
How We Calculate These Numbers
- Data Source
- All odds on this page come from The Odds API, which aggregates real-time lines from licensed US and offshore sportsbooks. We track moneyline, spread, and totals markets across every sport with active betting lines.
- Update Frequency
- We pull a fresh snapshot of every tracked market three times per day — at 6:00 AM, 2:00 PM, and 10:00 PM UTC. Each snapshot captures the latest lines from every sportsbook that has posted odds for a given event. The timestamp at the top of each page tells you exactly when the data was last refreshed.
- Vig Calculation
- Vig (short for vigorish, also called juice or overround) measures the margin a sportsbook builds into its odds. We calculate it by converting the odds on each side of a market to implied probabilities, summing those probabilities, and subtracting 100%. For example, a market priced at -110/-110 implies 52.38% on each side — a total of 104.76%, meaning a vig of 4.76%. Lower vig means better value for bettors because you keep more of your winnings.
- Per-Market Breakdown
- We compute vig separately for each market type: moneyline (h2h), point spreads, and totals (over/under). The "average vig" shown for each sportsbook is the mean across all market types weighted by the number of events sampled in each market.
- Grading Scale
- Every sportsbook receives a letter grade based on its average vig: A+ (under 2%) is exceptional and rare — these are typically sharp-friendly books. A (2–3%) is excellent. B+ (3–4%) is above average. B (4–5%) is the industry standard for most recreational sportsbooks. C (5–6%) is below average. D (above 6%) indicates high-juice markets where bettors face a steep cost per wager.
- Trend Tracking
- We store daily snapshots for 30 days, allowing us to show 24-hour and 7-day vig trends. A downward trend (improving) means sportsbooks are tightening their lines — often in response to increased competition or higher betting volume as a season heats up.