Author
Founder, OddsRelay
James is the founder of OddsRelay — the odds-data feed behind matched betting, arbitrage and odds-comparison products: 60+ UK bookmakers with bet365 included, matched against exchange lay prices and delivered as one clean, documented API. He writes here about how that data layer actually behaves — coverage, matching, freshness and the trade-offs — from the side that builds and runs it. The same feed powers a leading UK matched-betting platform today.
Arbitrage & value betting
Arbitrage is a relationship between prices across books and the exchange, not a single number. Here is the data behind it, how a real arb is detected, and why most of the signal is noise.
· 7 min read
Fundamentals
Asian handicap gives one side a goal head-start, which lets a bet half-win or half-lose. For your data that makes the line a field, not an afterthought. Here is how to model it.
· 6 min read
Exchange & lay data
Backing bets for an outcome; laying bets against it, and only an exchange lets you take that side. Here is the plain version, plus the back/lay data pair a matched feed hands you ready to use.
· 5 min read
Buying vs building
The best odds API for matched betting is the one that arrives already matched, not a raw price feed. Here are the criteria that decide it, and how the categories of option compare.
· 6 min read
Matched betting & oddsmatcher
Best odds guaranteed pays the larger of the price you took and the starting price. That single rule changes how a BOG bet has to be matched, and why the feed carries it as its own type.
· 5 min read
bet365 odds data
"Best bet365 odds API" has no literal answer, because bet365 publishes no API. Here is how the realistic options compare on the axes that decide whether the data is usable.
· 6 min read
Fundamentals
A bet builder combines several selections from one event into one priced bet. The price isn't the product of the legs, because the outcomes are correlated. Here's what that means for the data.
· 6 min read
bet365 odds data
bet365 is the book everyone wants and the hardest to cover well. This is the complete picture: what bet365 odds data is, what good coverage looks like, and how to put it to work without owning the collection problem.
· 5 min read
bet365 odds data
An arb involving bet365 is a relationship between its price and the best opposing price, so you need both sides, fresh, with real liquidity. Here's what makes the data usable, and why matched beats raw.
· 5 min read
Fundamentals
The overround, the margin, the vig: three names for the bookmaker's built-in edge. Here's how to compute it from decimal prices, and why comparing it across books tells you who to bet with.
· 5 min read
Buying vs building
The build-versus-buy question for an odds data layer turns on one thing: who owns the maintenance treadmill. Here is the honest breakdown, in effort rather than money, plus a checklist you can apply to your own situation.
· 6 min read
Buying vs building
A vendor-neutral framework for choosing an odds API. Five questions, asked in order, that separate a feed you can build on from one you'll regret. Raw book count is not one of them.
· 7 min read
Arbitrage & value betting
Closing line value is the gap between the price you took and the market's closing price, and beating it consistently is the clearest data-driven sign your bets carry an edge.
· 6 min read
Fundamentals
Decimal, fractional and American are three ways to write the same price. For anything you compute with, standardise on decimal, store decimal, and convert only at the point of display.
· 4 min read
Arbitrage & value betting
Dutching is what you reach for when there's no exchange to lay on: back the whole market across books so any result pays the same. Here's the data behind it.
· 7 min read
Emerging markets
The global aggregators have no South Africa region and don't list Nigeria's domestic books. Here's what emerging-market odds data really requires, the books that matter, and why maintained coverage beats a one-off capture.
· 6 min read
Exchange & lay data
A bookmaker back price is only half of a matched bet. This is the other half: what exchange and lay coverage is, the three exchanges we match against, and why the paired lay decides the opportunity.
· 6 min read
Fundamentals
Football is where odds data does most of its volume. This explains the main markets, how they're structured as event, market and selections, and how matched back/lay pairs work for football.
· 5 min read
Matched betting & oddsmatcher
Racing is where each-way and extra-place matched betting lives, and it is the most demanding odds data to model. Here is what makes it hard and what a matched feed delivers for it.
· 5 min read
Fundamentals
Odds data is a four-level hierarchy: event to market to selection to price, plus bookmaker, region and freshness metadata. Once the shape clicks, integrating a feed is straightforward.
· 5 min read
Fundamentals
An odds comparison site is a best-price table, and its data layer is the whole product. Here is what that layer has to do, and why normalisation, not raw prices, is the part that decides whether it works.
· 6 min read
Fundamentals
Markets get suspended or voided constantly, and a feed that hides those states will hand your users a wrong price. Here is how a good feed represents them, and what your product should do with each.
· 6 min read
Arbitrage & value betting
Building a sure-bet finder is two jobs. The detection maths is the fun part; the data layer underneath is the one most teams end up licensing. Here is why, and what it needs to deliver.
· 6 min read
Matched betting & oddsmatcher
Building an oddsmatcher means building two things: the data that feeds it, and the product around it. This is how to tell them apart, and which one is worth your engineering time.
· 6 min read
Fundamentals
You have the odds data; now you need to render it. A practical guide to mapping the response to rows, formatting decimal prices, showing the matched pair, and keeping it fresh.
· 6 min read
Buying vs building
A big book-count number is easy to print and easy to fake. Here's how to test a feed's coverage on depth, freshness and completeness, and verify it on a live dashboard before you commit.
· 6 min read
bet365 odds data
bet365 has no public API, so there are two honest routes to its odds: own the collection, or license a feed that already includes bet365 matched against exchange lay prices. Here's how to choose.
· 5 min read
Exchange & lay data
Betfair has a real public API, so you can pull its lay odds directly. This is how that route works, where it costs you, and the alternative that delivers lay already matched across three exchanges.
· 5 min read
Fundamentals
There are two ways to get bookmaker odds into your app: collect it yourself, or license a feed. Here's how each works, what to decide first, and the integration sketch for the faster path.
· 4 min read
Emerging markets
Nigeria's big domestic books have no official odds API, and the open-source options are fragile. Here are the honest routes to Nigerian bookmaker odds data, for the teams that actually need it.
· 5 min read
Emerging markets
South African books have no public APIs and the major aggregators have no SA region. Here are the two realistic routes to SA odds data, and why a maintained feed is the practical one.
· 6 min read
Fundamentals
Once an odds feed is live, three checks keep you honest: availability, freshness against the timestamp, and coverage of your books and markets. Here is how to build them so you catch a problem before your users do.
· 7 min read
Fundamentals
Different books name the same event and selection differently, so their prices don't line up on their own. This is how you normalise odds across bookmakers, and where it goes wrong.
· 6 min read
Fundamentals
Pricing a bet is four steps: implied probability, remove the overround, derive a fair price, then compare across books. Sharp books and exchanges give the best estimate of the true probability.
· 6 min read
Fundamentals
A feed gives you current prices; the history is what you persist from them. Here's a simple, durable model: timestamped snapshots keyed by event, market and selection, plus the retention trade-offs to decide up front.
· 6 min read
Buying vs building
The safe way to migrate off an odds provider is to run the new feed alongside your current one, diff it on your real traffic, and cut over only when it matches or beats what you have.
· 8 min read
Buying vs building
A hands-on checklist for evaluating an odds feed before you commit: get a trial key, call the endpoint, and check your own books, markets, freshness and the matched fields against how you'll actually use them.
· 6 min read
Fundamentals
Point an AI coding assistant at a public OpenAPI spec, describe what you want, and get a working odds-feed call to iterate on. Here's why a clean contract makes that work, and how to do it safely.
· 5 min read
bet365 odds data
bet365 has no public API, so every team building on its prices hits the same wall. Here's the honest landscape, and the option that gets you bet365 odds already matched against exchange lay prices.
· 5 min read
Emerging markets
Hollywoodbets publishes no odds API, so every team building on its prices hits the same wall. Here's the honest landscape and the route that gets its odds as maintained data.
· 5 min read
Fundamentals
Line movement is how a selection's odds shift as money comes in and information arrives. This is how odds data represents that movement, and what you can honestly read from it.
· 6 min read
Fundamentals
Live in-play and pre-match odds data are different problems with different costs. Here's how to tell which one your product actually needs before you shop, and why we ship pre-match and say so.
· 6 min read
Fundamentals
A full odds-data layer runs well past football and racing into tennis, cricket, rugby and basketball. Here is what multi-sport coverage really means, and why depth per sport beats a long list that thins out.
· 6 min read
Emerging markets
DIY and open-source Nigerian odds collection is fragile: coverage breaks when a book changes, and the open tools themselves admit some books go unreachable. That fragility is the strongest case for a maintained feed.
· 5 min read
Fundamentals
Builders hit two terms for the same data and assume they're choosing between products. They aren't. Here's what each word stresses, and the distinction that actually changes your build: raw versus matched.
· 5 min read
Fundamentals
A sports data API delivers scores, fixtures and player stats. An odds API delivers bookmakers' prices for outcomes. They're different products, they're often used together, and only one is what matched betting runs on.
· 5 min read
Buying vs building
Reliability for an odds feed is two things, not one: uptime and freshness. Here is how to read an SLA honestly, and why a figure you can check on a live dashboard beats a number you are asked to trust.
· 5 min read
Matched betting & oddsmatcher
An oddsmatcher finds the best back/lay pairs across books and exchanges. Here is the data behind it: each back price matched to an exchange lay price, with a rating that shows how close the two are.
· 6 min read
Fundamentals
Over/under markets price whether goals, points or corners finish above or below a line. For data, the line is part of the selection: here is why that changes how you compare, match and arb totals across books.
· 5 min read
Fundamentals
How to poll an odds feed without wasting bandwidth or hitting rate limits: poll on the refresh cadence, send If-None-Match for a cheap 304 when nothing has changed, and accept gzip.
· 5 min read
Matched betting & oddsmatcher
Two fields decide whether a matched bet is worth placing: the rating and the qualifying loss. Here is what each one means, conceptually and honestly, and how a matched feed computes them for you.
· 5 min read
Buying vs building
An odds-data supplier licenses feed access to licensed builders; it stays out of the wager itself. Here's what a responsible supplier does, and why it matters for how the product is built and sold.
· 5 min read
Emerging markets
Good South African odds coverage is not the global books alone. It is the domestic books bettors actually use, across PSL soccer, rugby and cricket. Here is what that looks like as a data problem.
· 6 min read
Arbitrage & value betting
Sure bets disappear fast for three reasons: prices move, accounts get limited, and stale feeds show arbs that already closed. Here's the honest picture, and what good data does about it.
· 5 min read
Fundamentals
What every field in a good odds API response is for, walked one at a time: the event/market/selection keys, the back and lay blocks, rating and qualifying_loss, and the envelope around them.
· 6 min read
Exchange & lay data
Betfair delays data on a delayed application key; live, undelayed prices need a live key that meets Betfair's requirements. Here's what that means for your build, and when it matters.
· 5 min read
Matched betting & oddsmatcher
Matched betting runs on one thing: a bookmaker back price paired with the current exchange lay price, with a rating and qualifying loss attached. This is the complete picture of that data layer, and how to ship it without building the matcher.
· 7 min read
Matched betting & oddsmatcher
Each-way and extra-place offers can't be expressed as a single back/lay pair. Here is the extra data they need, and how an each-way feed carries the place terms and the two-part matched calculation.
· 6 min read
Buying vs building
A tipster platform lives or dies on the odds it prices tips with. Here is the data layer underneath: broad coverage with bet365, identifiers that hold across time, and freshness enough to record the price when a tip goes out.
· 5 min read
bet365 odds data
DIY bet365 looks like a one-off build and turns into a permanent maintenance job. Here's the true ongoing burden, what it costs your actual product, and when building is still the right call.
· 6 min read
bet365 odds data
Matched betting on bet365 isn't about the back price alone. Here's the data an oddsmatcher actually needs: the bet365 back paired with a live exchange lay, with rating and qualifying loss attached.
· 5 min read
Arbitrage & value betting
Arbitrage and value betting look similar from the outside and differ sharply underneath. Here is the comparison from a data angle: different risk profiles, different data needs, one feed that serves both.
· 5 min read
Fundamentals
Odds change continuously, not at discrete events, so polling with ETag/304 fits the data better than webhooks. Here's the plain comparison, and why OddsRelay is pull-based.
· 5 min read
Matched betting & oddsmatcher
Oddsmatcher-ready data arrives already matched, with the exchange lay price, rating and qualifying loss attached, so you render rows instead of building a matcher. Here is exactly what the term removes from your build.
· 6 min read
Buying vs building
Buyers searching for odds-feed pricing want to understand value, not just a quote. Here are the handful of things that actually move the cost, and why the cheapest raw feed is rarely the cheapest to run.
· 7 min read
Exchange & lay data
A betting exchange lets bettors bet against each other, backing or laying, with the exchange taking commission. Its lay prices are the other half of every matched and arbitrage pair.
· 5 min read
Fundamentals
An odds API hands your software bookmakers' prices as structured data instead of a human reading betting sites by hand. Here's what one returns, how raw and matched feeds differ, and what to check before you commit.
· 6 min read
Arbitrage & value betting
Most arb feeds look fine in a demo and fall apart in production. Here are the four things that actually decide whether a feed is usable, plus the exchange-lay side that back/lay arbs live or die on.
· 6 min read
Exchange & lay data
A great lay price with no money behind it is a phantom. Here's what lay liquidity is, why a matched feed carries a liquidity figure on every row, and how to gate opportunities by it.
· 5 min read
Buying vs building
Collecting your own odds works until a book changes. Then it's a treadmill of breakage, stale prices and on-call, for no product differentiation. Here's when teams stop and buy a feed instead.
· 5 min read
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