In WTA tennis, spread betting — commonly referred to as game handicaps — involves a player receiving or giving a set number of games across the match. For example, a -4.5 spread on Iga Świątek means she needs to win by at least five more games than her opponent across all sets played. This differs fundamentally from team sport spreads because tennis scoring is non-linear; a player can dominate in games won yet still lose in sets, making the game spread a distinct market from the match winner or set betting lines.
The spreads market at the Madrid Open becomes particularly valuable when there are mismatches on clay, where surface specialists can dominate players uncomfortable on the slower surface. Bettors should watch for fatigue factors in this Masters-level event — players competing in back-to-back clay tournaments often see their margins shrink in later rounds, creating value on underdogs covering large spreads. Regarding vig, game spreads in WTA events typically carry slightly higher juice than moneyline markets, often landing in the -110/-110 to -115/-105 range. This is partly because sharper action concentrates on totals and match winners, leaving spreads with marginally less efficient pricing — which can actually create opportunities for bettors who do the work.
Cross-Sport spreads Vig Comparison
WTA Madrid Open spreads averages 6.04% vig across 10 sportsbooks. Here's how that compares to other active sports:
| Sport | Avg Vig | vs WTA Madrid Open |
|---|---|---|
| WTA Madrid Open | 6.04% | — |
| CFL | 5.22% | 0.82% higher |
| NCAAF | 4.69% | 1.34% higher |
| NFL | 4.78% | 1.26% higher |
| NFL Preseason | 4.37% | 1.66% higher |
Vig Rankings
| # | Sportsbook | Vig | Grade | Events |
|---|---|---|---|---|
| 1 | Pinnacle | 2.88% | A | 1 |
| 2 | BetOnline.ag | 4.05% | B | 1 |
| 3 | LowVig.ag | 4.05% | B | 1 |
| 4 | betPARX | 6.07% | C | 1 |
| 5 | Bally Bet | 6.07% | C | 1 |
| 6 | BetRivers | 6.07% | C | 1 |
| 7 | Bovada | 6.93% | C | 1 |
| 8 | BetUS | 6.93% | C | 1 |
| 9 | ReBet | 8.26% | D- | 1 |
| 10 | Caesars | 9.04% | D- | 1 |
Frequently Asked Questions
Which sportsbook has the lowest WTA Madrid Open spreads vig?
Pinnacle currently has the lowest vig at 2.88%, earning a grade of A.
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.