About Smarter Trades

Who runs Smarter Trades?

Smarter Trades is owned and edited by Alex Carter. The site is independent and is not affiliated with Betfair or any bookmaker/exchange. All opinions and worked examples are informational and not betting advice.

Author & site owner

Alex Carter is the owner and editor of Smarter Trades. Alex builds lightweight betting exchange tools focused on staking, liability and expected value so that traders can sanity-check their numbers before placing a bet.

• 12+ years of hands-on Betfair exchange trading and market analysis.
• Background in quantitative risk analysis and spreadsheet-based modelling for staking plans.
• Focus on transparent, browser-based calculators that show the full maths behind each result.

Content is reviewed on a rolling basis. Calculator pages are checked after major Betfair rule/commission updates and at least quarterly for accuracy, with any reader feedback triaged within two weeks. Updates are verified against official Betfair documentation, exchange rulebooks and the underlying formulae used in each tool.

What the calculators are (and are not) for

The dutching, lay, hedge, EV and Kelly calculators are designed to help you understand:

• how much you are risking when you lay a selection;
• how your stake can be split across multiple outcomes;
• whether your estimated edge is positive or negative on a given price;
• how your bankroll might grow (or shrink) over time with different staking plans.

They are not tipster tools and do not tell you what to back or lay. The inputs come from your own analysis and judgement, and the tools simply turn those inputs into clearer numbers.

Responsible gambling

Betting and trading on sports always involves risk. You can lose money very quickly if you stake more than you can afford or misjudge probabilities. You should only bet with money you can afford to lose and you should take a break if gambling stops being enjoyable.

If you feel your gambling is becoming a problem, please seek help from a recognised support service such as BeGambleAware or your local equivalent.

Our methodology

Every calculator on Smarter Trades is built from first principles. We start with the mathematical formula — whether that is the Kelly criterion, the dutching inverse-odds method, or the standard lay liability equation — and implement it directly in browser-based JavaScript. No server-side processing is involved, so your inputs never leave your device.

Before a calculator is published, it goes through a three-stage verification process:

• Formula validation: The underlying equation is checked against published academic and industry sources (e.g. the original Kelly paper, Betfair's own help documentation, and standard probability theory textbooks).
• Worked example testing: At least three worked examples are calculated by hand and compared against the calculator's output. Any discrepancy is investigated and resolved before launch.
• Edge case review: Extreme inputs (very high odds, very small stakes, zero commission) are tested to ensure the calculator handles them gracefully without producing misleading results.

After publication, calculators are re-tested at least quarterly and whenever Betfair announces changes to commission rates or market rules.

Sources we reference

Our guides and calculators draw on the following authoritative sources:

• Betfair Help Centre — official documentation on how exchange betting, commission, and market settlement work.
• J. L. Kelly Jr., "A New Interpretation of Information Rate" (1956) — the original paper introducing the Kelly criterion for optimal bet sizing.
• UK Gambling Commission — regulatory guidance on responsible gambling, operator licensing, and consumer protection.
• BeGambleAware.org — independent charity providing information and support for anyone affected by gambling.
• Standard probability and statistics references — including expected value theory, binomial distribution for variance modelling, and Bayesian updating for probability estimation.

How we keep content accurate

Content accuracy is central to Smarter Trades. Our review process includes:

• Quarterly content audits: Every guide and calculator page is reviewed at least once per quarter. Outdated examples, broken links, and stale references are updated or removed.
• Reader feedback triage: Corrections or suggestions submitted through the contact form are reviewed within two weeks. Confirmed errors are corrected promptly, and the page's "last reviewed" date is updated.
• Commission and rule monitoring: When Betfair or other exchanges change their commission structures or market rules, affected calculators and guides are updated within two weeks of the change taking effect.
• Transparent corrections: If a material error is found in a published guide, the correction is noted at the top of the page so readers know the content has been revised.

For full details, see our Editorial Policy.

Contact

If you spot an error in one of the calculators, would like to suggest an improvement or want to request a new tool, you can get in touch using the contact form.