How Is the Bet105 Vig Index Calculated?
Answer: The Bet105 Vig Index measures our two-way
hold percentage — the built-in margin priced into a market — computed
directly from Bet105’s own offered odds on every core two-way market that took
action during the quarter. We report hold % as the primary figure and translate
it into familiar −105 / −107 / −110 “effective juice.” This
page documents exactly how the number is produced, what it does and does not
cover, and where our reference-pricing figures for other books come from.
Key Takeaways
- Metric: two-way hold % = (implied probability of side A +
implied probability of side B) − 100%. - Source: Bet105’s own platform pricing data.
- Markets: full-game moneyline, point spread, and total.
- Sample: markets that took real action during the quarter —
representative of liquid, actively traded lines, not a full board scan. - Cadence: refreshed quarterly on the most recent complete
quarter. - Other books: shown separately as published/advertised
standard pricing with sources — not a Bet105 measurement.
The Metric: Two-Way Hold %
Every set of American odds implies a probability:
- Negative odds: implied probability = −odds ÷ (−odds + 100). Example: −110 → 110 ÷ 210 = 52.38%.
- Positive odds: implied probability = 100 ÷ (odds + 100). Example: +120 → 100 ÷ 220 = 45.45%.
For a two-way market we add the implied probabilities of both sides. The
amount they exceed 100% is the hold (the vig). A market priced
−110 / −110 sums to 104.76%, i.e. a 4.76% hold. We compute this for
each market, then average across all markets in a category to produce the Index
value. The “effective juice” column is the symmetric two-sided price that
produces the same hold, shown only as a reader-friendly translation — the hold %
is the canonical number.
Odds Source
Bet105 figures are drawn from our internal pricing and wagering records — the
actual odds offered to customers on our platform. No third-party or modeled odds
are used for the Bet105 Index itself.
Market Selection
The Index covers the three core two-way markets that make up the large
majority of betting volume and are directly comparable across sportsbooks:
- Moneyline (full game)
- Point spread (full game)
- Total / over-under (full game)
Player props and other specialty markets are excluded from the headline
figures. They are priced differently, are harder to compare like-for-like across
books, and have thinner, less consistent data — including them would reduce the
reliability of the Index rather than improve it.
Sample and Coverage (Full Disclosure)
The Index is built from markets that took real action during
the quarter. This is a large, representative sample of our liquid, actively
traded lines — Q2 2026 covered more than 13,000 measured core markets — but it
is not a scan of every line we ever posted. Because it reflects
markets bettors actually engaged, it is weighted toward popular games and main
lines. We state this openly rather than imply full-board coverage.
Update Frequency
The Vig Index is refreshed quarterly, each edition using the
most recent complete calendar quarter. The current edition covers Q2 2026
(April 1 – June 30, 2026). The visible “last updated” date on the
Vig Index page always reflects the live edition.
How We Handle Other Sportsbooks
The Vig Index page includes a reference table of published or
advertised standard pricing for other sportsbooks (for example, the
industry-standard −110). These figures:
- reflect commonly cited standard prices, with sources;
- are not measured using Bet105’s methodology;
- are presented separately, never merged into a single ranked league table
with our measured data.
A future edition will add a fully matched, live-odds comparison — capturing
competitor odds on the same games and markets at the same time — to enable a true
apples-to-apples multi-book Vig Index. Until that data is collected and
verified, we keep measured and published figures clearly separated.
Definitions
| Term | Definition |
|---|---|
| Vig / juice / hold / margin | The built-in edge a sportsbook prices into a market. |
| Two-way hold % | How far the two sides’ implied probabilities sum above 100%. |
| Implied probability | The probability embedded in a set of odds (see formulas above). |
| Effective juice | The symmetric two-sided American price that yields a given hold (a translation of hold %). |
| De-vig / fair odds | Odds with the hold removed, estimating the true implied probability. |
Frequently Asked Questions
What data is the Bet105 Vig Index based on?
Bet105’s own offered odds on core two-way markets that took action during the
measured quarter. It is measured data from our platform, not a marketing
estimate.
Why do you separate Bet105’s figures from other books’ figures?
Because they are measured differently. Bet105’s numbers come from real market
data; other books’ figures are their published standard pricing. Merging them
into one ranking would imply a like-for-like comparison we have not yet made, so
we keep them clearly separate.
Does the Index cover every market Bet105 offers?
No. It covers full-game moneyline, spread, and total — the core two-way
markets — and is based on lines that took action, which represents liquid,
actively traded markets rather than a full board scan.
How often is the methodology or data updated?
The data refreshes quarterly. This methodology page is updated whenever the
calculation, market selection, or sourcing changes.
Related Guides
- The Bet105 Vig Index
- What Is a Low Vig Sportsbook?
- Expected Value (EV) in Betting
- Sharp Sportsbooks Hub