Horse racing odds
If the exchange offers 6.0 and the bookmaker offers 5/1, the bookmaker is competitive after commission. The practical approach for most punters is to use both. When should you use the exchange, and when should you use a bookmaker?
A horse at 2/1 rugby betting not on gamstop (33% implied probability) that you assess as a 25% chance is not—even though the shorter price might feel safer. A horse at 4/1 (20% implied probability) that you assess as a 25% chance is a value bet. The more fundamental question is whether those odds represent value—whether the implied probability understates the horse’s true chance of winning.
You want the best place to bet on horses, at BUSR you can bet from anywhere.
At 1/5 odds, your 10/1 shot returns just 2/1 (plus stake) on the place portion. These are standard industry terms, but bookmakers frequently enhance them for major races or as ongoing promotions. If prices consistently drift after you bet, something in your analysis may need adjustment. Value exists in the gap between your probability assessment and the bookmaker’s implied probability.
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. Check the exchange price on your selection before placing with a bookmaker. 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.
The commission you pay on an exchange winning bet reduces your effective odds. There is a subtlety that experienced exchange users understand and newcomers often miss. The back price might be 6.0 but only fifty pounds is available at that price, and the lay price might be 7.0 — a gap that represents poor value for anyone trying to trade. That difference — roughly 10 per cent on the individual price — is the cost of the bookmaker margin. The exchange takes a commission on the net winnings of the winning side, typically between 2 and 5 per cent depending on the user’s activity level. Instead of setting odds and accepting bets against them, the exchange matches punters on opposite sides of a bet.
If your selections consistently close shorter than the price you took, your assessment method is adding value. The days when betting shops competed fiercely on price have given way to an era where online platforms sometimes offer “good enough” pricing, knowing many customers will not check elsewhere. Before placing multiple bets, check the specific bookmaker’s terms—assuming BOG applies universally is a common and costly mistake. BOG is a tool for capturing extra edge when your original selection was sound; it does not substitute for sound selection. Identify horses where you see value relative to implied probability.
The sum of implied probabilities across all runners in a race reveals the bookmaker’s overround. The difference (28% vs 22.2%) represents potential value—the bookmaker is underestimating this horse’s chances according to your analysis. At decimal odds of 6.00, a £10 bet returns £60 total—your £10 stake plus £50 profit. The first number represents potential profit; the second represents the stake required to generate that profit. At 7/2, the same £1 stake returns £3.50 profit plus stake, totalling £4.50.
For odds comparison across multiple bookmakers, decimal format saves time and reduces errors. This format dominates betting exchanges and has become standard on many online platforms, particularly for European customers. At 4/6 (sometimes written 4-6), you need to stake £6 to win £4 profit, returning £10 total from a £6 stake.
