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. 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.
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 bookies not on gamstop 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.
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. Small-field races with well-fancied favourites tend to carry lower overrounds (closer to 110 per cent) because the market is more efficient and bookmakers compete harder on the headline price of the favourite. The difference between 5/1 and 6/1 on the same horse in the same race is a 20 per cent increase in profit — free money, essentially, for the 30 seconds it takes to check a second bookmaker. Odds expressed in decimals are meant to show the total payout the punter receives, which includes the winnings and the stake.
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?
With the assistance of Equinedge I hit several races yesterday and netted over $1100 in profit. 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. This is much simpler as the decimal figure is simply the payout per unit staked.
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 per cent.
Betting on the outcome of horse racing can be fun and profitable, and if you know what you’re doing, you might even be able to beat the odds. Not only that, you’ll get up to an 10% rebate on all your horse bets placed! Get the VIP treatment from day one with a special Welcome Bonus up to $1,000.
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.
The overround on the Grand National ante-post market can reach as high as 180 per cent — a level that would be considered predatory in any raceday market. It varies by operator, by race type, and by the time of day. If Bookmaker A is running a 115 per cent book on a race and Bookmaker B is running a 125 per cent book, Bookmaker A is systematically offering better value across the entire field.