In WTA tennis, spread betting — commonly referred to as game spreads or handicaps — involves one player giving or receiving a specified number of games across the match. For instance, a -4.5 game spread on Iga Swiatek means she needs to win by at least five more games than her opponent combined across all sets. This differs fundamentally from team sport spreads; in tennis, the spread accounts for the total game differential rather than a single scoring metric, making blowout potential and service dominance critical factors in evaluation.
The WTA Canadian Open, played on hard courts in Montreal or Toronto, often produces volatile scorelines due to the surface's relatively neutral characteristics and the condensed nature of early-round matchups between top seeds and qualifiers. Spread betting becomes most valuable when bettors identify mismatches where the moneyline offers little return but the game spread still presents exploitable margins — particularly when a dominant server faces an opponent with weak return statistics. Regarding vig, tennis spreads typically carry slightly higher juice than moneylines because books face greater liability modeling game differentials. Bettors should compare spread vig carefully across books, as even small differences in the -110 to -115 range compound significantly over a full tournament's worth of wagers.
Analysis updated September 20, 2026. Odds data above refreshes hourly.
Cross-Sport spreads Vig Comparison
WTA Canadian Open spreads averages 6.44% vig across 10 sportsbooks. Here's how that compares to other active sports:
| Sport | Avg Vig | vs WTA Canadian Open |
|---|---|---|
| WTA Canadian Open | 6.44% | — |
| ATP China Open | 6.41% | WTA Canadian Open runs 0.03 pts higher |
| ATP Japan Open | 6.09% | WTA Canadian Open runs 0.35 pts higher |
| WTA China Open | 6.59% | WTA Canadian Open runs 0.15 pts lower |
| CFL | 5.11% | WTA Canadian Open runs 1.33 pts higher |
Vig Rankings
Frequently Asked Questions
Which sportsbook has the lowest WTA Canadian Open spreads vig?
Pinnacle currently has the lowest vig at 4.51%, 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 every hour, on the hour (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 average vig: A+ (under 2%) is exchange-level pricing, A (2–3%) very competitive, B+ (3–4%) above average, B (4–5%) the industry standard, C+ (5–6%) slightly below average, C (6–7%) below average, D (7–8%) high vig, D− (8–10%) very high, F (10%+) predatory.
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, BetAnything). 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 every hour, on the hour (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.