Spread betting in the NBA Summer League works the same way as regular-season NBA games — the favored team must win by more than the posted number for a spread bet to cash, while the underdog can lose by fewer points than the spread (or win outright) to cover. However, Summer League spreads carry a unique layer of uncertainty. Rosters are filled with rookies, undrafted free agents, and players fighting for roster spots, which creates enormous variance. Lines are typically tighter than regular-season games, with most spreads falling between 1 and 5 points, reflecting the general parity among these developmental squads.
Bettors should pay close attention to which lottery picks and key rookies are actually suiting up each game, as late scratches can dramatically shift value after the line is set. Games later in the tournament schedule also tend to see heavier rest or minute restrictions for top prospects, creating exploitable mismatches. When it comes to vig, Summer League spreads often carry slightly higher juice than regular-season NBA lines — it's not uncommon to see -115 on both sides rather than the standard -110 — because books account for the lower betting volume and higher unpredictability. Comparing vig across sportsbooks becomes especially important in this market, where that extra juice can quietly erode margins over a short schedule.
Cross-Sport spreads Vig Comparison
NBA Summer League spreads averages 5.87% vig across 17 sportsbooks. Here's how that compares to other active sports:
| Sport | Avg Vig | vs NBA Summer League |
|---|---|---|
| NBA Summer League | 5.87% | — |
| CFL | 5.17% | 0.70% higher |
| NCAAF | 4.87% | 1.00% higher |
| NFL | 4.84% | 1.03% higher |
| NFL Preseason | 4.85% | 1.02% higher |
Vig Rankings
| # | Sportsbook | Vig | Grade | Events |
|---|---|---|---|---|
| 1 | LowVig.ag | 3.84% | B+ | 2 |
| 2 | BetOnline.ag | 4.76% | B | 2 |
| 3 | BetUS | 4.76% | B | 2 |
| 4 | ReBet | 5.02% | C+ | 2 |
| 5 | FanDuel | 5.30% | C+ | 3 |
| 6 | Bovada | 5.35% | C+ | 3 |
| 7 | BetMGM | 5.35% | C+ | 3 |
| 8 | Fanatics | 5.41% | C+ | 3 |
| 9 | DraftKings | 5.43% | C+ | 3 |
| 10 | Hard Rock Bet | 5.75% | C+ | 3 |
| 11 | Pinnacle | 5.76% | C+ | 3 |
| 12 | MyBookie.ag | 5.90% | C+ | 3 |
| 13 | Caesars | 6.20% | C | 3 |
| 14 | BetAnything | 6.98% | C | 2 |
| 15 | theScore Bet (ESPN Bet) | 7.28% | D | 3 |
| 16 | BetRivers | 8.05% | D- | 3 |
| 17 | Fliff | 8.66% | D- | 3 |
Frequently Asked Questions
Which sportsbook has the lowest NBA Summer League spreads vig?
LowVig.ag currently has the lowest vig at 3.84%, earning a grade of B+.
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 exchange-level pricing. A (2–3%) is very competitive. B+ (3–4%) is above average. B (4–5%) is the industry standard — a -110/-110 line is 4.76%. C+ (5–6%) is slightly below average. C (6–7%) is below average. D (7–8%) is high vig. D− (8–10%) is very high vig. F (10%+) is predatory pricing. See the full Vig Index Methodology for formulas, worked examples, and known limitations.
- 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.