Online Racebook Betting
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.
Most bookmakers cap BOG payouts — some at a maximum enhanced payout of 500 pounds, others at a maximum uplift of a certain number of odds points. 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 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. Using the exchange as a benchmark — even if you ultimately bet with a bookmaker — is one of the most effective habits a punter can develop. The practical approach for most punters is to use both. If you back at 6.0 (5/1) and pay 5 per cent commission on your winnings, your effective odds are 5.75 (approximately 19/4). On a Monday afternoon novice hurdle at a minor track, liquidity is thin. Over time, backing at exchange odds rather than bookmaker odds produces a measurably higher return on investment, assuming you can find liquidity on your chosen market.
On the raceday market itself, there are consistent patterns. Ante-post markets on the Cheltenham Gold Cup or Champion Hurdle typically run between 140 and 160 per cent, which is lower than the National but still significantly wider than raceday. The aggregate effect across 20 runners adds up to a much wider margin than in a six-runner race. 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.
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.
In practice, they always sum to more — typically between 110 and 130 per cent for horse racing — and that excess is the overround. In a perfectly fair market with no margin, the implied probabilities of all runners in a race would sum to exactly 100 per cent. Understanding those differences is where value lives. The bookmaker margin is built into every price, but how wide that margin is varies enormously between operators, between race types, and between the fixed-odds market and the betting exchange.
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 best sports betting sites not on gamstop 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).
Around major meetings — Cheltenham, the Grand National, Royal Ascot — bookmakers offer boosted prices on selected runners. If the exchange offers 6.0 and the bookmaker offers 5/1, the bookmaker is competitive after commission. Instead of setting odds and accepting bets against them, the exchange matches punters on opposite sides of a bet.