Comparison checklist
- Write the exact event, market, selection and settlement period.
- Capture every price within a short, recorded window.
- Confirm the price is available for the intended stake; Betfair's exchange guide distinguishes displayed prices, available amounts and matching.
- Apply commission, deductions or promotion conditions.
- Calculate net profit on one common stake.
- Save the accepted receipt or record that no bet was placed.
Worked comparison
For a 100-unit winning stake:
| Source | Headline odds | Adjustment | Net profit |
|---|---|---|---|
| Sportsbook A | 2.08 | none in example | 100 x (2.08 - 1) = 108.00 |
| Sportsbook B | 2.12 | 10-unit maximum at price | 10 x (2.12 - 1) = 11.20 on available size |
| Exchange | 2.15 | illustrative 5% commission | 100 x (2.15 - 1) x 0.95 = 109.25 |
For a full 100-unit stake under these assumptions, the exchange has the highest illustrative net profit. Sportsbook B has the highest fixed-odds headline but only for 10 units.
Settlement parity
DraftKings' soccer rules and Betfair's sportsbook rules show why operator rules must be checked. A match-result market may use regulation time while another label refers to qualification or includes extra time.
Exchange-specific treatment
Betfair's exchange guide distinguishes available amounts and matched requests. Its commission guide says the applicable rate varies. Do not apply one illustrative rate to every account or platform.
Reporting the result
A reproducible comparison records source, URL or market ID, captured price, size, timestamp, commission assumption and settlement definition. This turns "best odds" into a bounded observation rather than a permanent ranking.
Calculate a blended price when size is limited
If the intended stake cannot be placed at one price, compare the actual combination rather than the highest cell. Suppose 20 units are available at 2.20 and the remaining 80 units at 2.08. Total winning gross return is 20 x 2.20 + 80 x 2.08 = 210.40 units. Dividing by the 100-unit stake gives a blended decimal price of 2.104. That is more informative than advertising 2.20 for the whole order.
Run the same calculation after commission or deductions using the rule that applies to each source. Promotions should be a separate row because eligibility, cap and expiry can prevent a permanent like-for-like comparison.
Reproducibility standard
A second reader should be able to answer:
- Which exact selection and settlement period were compared?
- When were the prices captured?
- How much was executable at each level?
- Which account-specific cost assumptions were used?
- Was a price accepted, rejected or only observed?
If any answer is missing, describe the result as an indicative snapshot. A well-documented comparison may conclude that no clean ranking is possible; that is more useful than forcing a best-price claim from incompatible products.
Related resources
Use exchange versus bookmaker odds for product differences and overround for complete-market comparison.
Continue learning
- Next guide: How to Calculate Betting Returns and Profit
- Related guide: How to Calculate Bookmaker Overround
Assumptions and limitations
The table is illustrative and not a live operator comparison. Prices, limits and eligibility can change between capture and acceptance. Better price improves the payoff for the same winning selection, but does not establish a positive probability edge.
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