If you are betting early in the day and BOG is on offer, take the best available bookmaker price. If the exchange back price is 8.0 and the best bookmaker is offering 6/1, the bookmaker is taking a significantly wider margin on that horse. Here is the workflow that experienced punters follow, stripped of anything unnecessary. And some operators apply BOG only to bets placed after a certain time in the morning, which means very early ante-post-style wagers do not qualify. 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.
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.
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. 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.
At the upper end, you find big-field handicaps with 20 or more runners, where each horse price can be inflated by a few ticks without any individual punter noticing the difference. The individual difference may be small — perhaps 5/1 versus 11/2 — but across hundreds of bets over a year, that cumulative margin is the difference between a profitable punter and a losing one. The take varies from state to state and the money is used to pay taxes, purse money for the horsemen, expenses at the track, and the track’s profit. 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.
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. 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.
This includes first time starters. Our top Pace number will be in either the 1st or 2nd position at the first call 72.5% of the time. Our top win percentage horse wins 32.9% of the time.
The overround also tells you something about the race itself. The overround is 5.9 per cent, meaning the bookmaker has built a theoretical edge of just under 6 per cent into the market. It is the bookmaker’s theoretical profit margin before a non gamstop betting 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 per cent.
For any given horse, you can see the best available price highlighted, and the difference between the best and worst price is often two or three points of odds — the difference between 7/1 and 5/1 on the same horse in the same race. It does not require you to do anything special — just take an early price on a race where BOG is offered. 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.