Horse Racing Odds
If the exchange is at 7.0 and the bookmaker is at 6/1, the prices are closer, and after exchange commission the bookmaker might even be marginally better. Oddschecker is the most widely used in the UK and shows prices from all major bookmakers side by side, updated in near-real time. If the exchange offers 7.0 and the bookmaker offers 5/1, the bookmaker is taking a significantly larger margin on that runner, and you should either back on the exchange or find a bookmaker whose price is closer to the exchange level.

The value of BOG depends on how much Starting Prices drift from the early prices. That decline puts pressure on bookmakers to attract and retain bettors. It is a one-way ratchet in the punter’s favour — a free option on upward price movement with no downside risk. Check the exchange price on your selection before placing with a bookmaker. When should you use the exchange, and when should you use a bookmaker? There is a subtlety that experienced exchange users understand and newcomers often miss.
Across UK and Irish horse racing, typical bookmaker overrounds range from about 110 to 130 per cent. Understanding the typical ranges gives you a framework for evaluating whether the price you are being offered is competitive or padded. The margin a bookmaker builds into horse racing odds is not fixed. If you bet at a bookmaker with a consistently higher overround, you need a higher strike rate just to break even. The worst overrounds appear in ante-post markets, where the uncertainty justifies — in the bookmaker’s view — margins that can reach extraordinary levels. The overround also tells you something about the race itself.

Where a bookmaker might offer 5/1 on a horse with a 120 per cent book, the exchange might show 5.5 (or 9/2 in fractional terms) on the same runner with a total market overround of 103 per cent. When bookmakers extend place terms on big handicaps — paying five or six places instead of four — they compensate by widening the margin on the place element of each-way bets. At the lower end, you find small-field Flat races — Group 1 contests with five or six runners where the form is well established and bookmakers compete aggressively on the headline price of the favourite. The difference between 3/1 and 7/2 is not dramatic on a single bet, but across 200 bets over a season it represents dozens of units of profit or loss.

On horses that drift — less money than expected, price lengthening — BOG gives you the benefit of the higher SP. On horses that are supported in the market — money coming in, price shortening — BOG adds nothing, because uk betting sites the SP is lower than the price you took. Best Odds Guaranteed is one of the most powerful tools available to horse racing punters, and it is routinely undervalued.

On short-priced selections — odds-on or evens — the exchange commission can actually make the bookmaker price competitive or even better, because the commission is a fixed percentage of the profit regardless of the odds. The commission you pay on an exchange winning bet reduces your effective odds. On feature races — the Champion Hurdle, the Gold Cup, the Grand National, Saturday afternoon handicaps at major tracks — the exchange market is deep enough that you can back at the displayed price without difficulty.
The betting exchange — Betfair being the dominant platform — operates on a fundamentally different model to a traditional bookmaker. Among fixed-odds bookmakers, bet365, Paddy Power, and William Hill tend to be competitive on feature races, while some smaller operators run wider books, particularly on less prominent meetings. By the time the race starts, competition among operators has usually tightened the market.
Although it won’t tell you how much the horse will pay, it does show the amount of profit you will get if you win and the amount you have to bet to get it. The figures indicate how much a punter would win using a stake of a $100. The money line is mostly used by the American bookies, which clearly displays an underdog, and a favorite.
Flutter Entertainment, which owns Betfair, reported global revenue of $14 billion in 2024 across 13.9 million average monthly users, but the exchange is only one part of that portfolio, and liquidity varies enormously by market. Hundreds of thousands of pounds are matched, and the spread between the back and lay prices is narrow. That difference — roughly 10 per cent on the individual price — is the cost of the bookmaker margin. One person backs a horse to win; another lays it (bets against it winning).