Horse Racing Odds
Dave Massey previews Saturday’s action at Aintree, selecting his best bets for the races at 1.15, 1.45, 2.25 and 3.00. Dave Chisnall spoke to kwiff on Friday afternoon just before he kicked off his Grand Slam of Darts qualifying campaign That small time investment — repeated across every bet you place — is the most reliable edge available to the average punter.
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).
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. Checking the overround before you bet is not something most punters do, but it takes less than a minute with a calculator or an odds comparison site.
It is the bookmaker’s theoretical profit margin before a single bet is settled. 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 betting account without gamstop 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. Horse Racing Odds Comparison — More on this topic at horse racing bookmakers.
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). 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. Bookmakers open with a cautious book and adjust as money comes in. The first show of prices in the morning — often called the early prices — tends to carry a wider margin than the Starting Price. 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.
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. 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.
Unlike free bets, which come with qualifying conditions and wagering requirements, BOG applies to every qualifying bet you place. A few bookmakers restrict BOG to races shown on ITV or feature meetings, excluding the smaller afternoon cards where drifts are more common. That means BOG triggers on a meaningful proportion of bets, and the average uplift when it does trigger is typically between half a point and two full points of odds. Research on UK racing suggests that around 35 to 40 per cent of runners drift to a higher SP than their morning price.
