“Best Book” is one of those terms that’s more complex than it seems. Basically, it’s the one bookie who’s offering the best odds on an event – the one offering themselves the smallest cut.
In order to understand why this is so crucial, you have to know how bookmakers work. They don’t just give fair prices and hope for the best. Instead, they add what is known as an “over-round” – basically their margin of profit incorporated into each market that they enter.
Let me give you a simple illustration that’ll make this as plain as a bell. Suppose there is a five-horse race where each horse has a fair chance of winning. In a perfectly fair world, each horse would be quoted at 4/1, with each having a 20% chance. If you backed all five horses at those odds, you’d get your fiver back regardless of which one won – finishing level every time.
But bookmakers aren’t running charities, are they? So instead of taking 4/1 on each horse, they will take them all 3/1. Now each horse will have an implied probability of 25% from the odds, and if you sum up all five probabilities, you will get 125%. The other 25% is the bookie’s over-round – his margin.
The “best book” is simply that with the lowest over-round percentage. If Bookie A has an over-round of 15% on a given market and Bookie B has an over-round of 25% on the same event, then Bookie A is offering the best book. You’re getting better value for your dollar because they’re taking less out of the pie.
This is better than most punters realize. In the long term, constantly betting with bookmakers whose over-rounds are minimal can make a massive impact on your overall performance. It’s swimming upstream with a light current against swimming against a raging torrent.
In practice, over-rounds vary enormously from bookmaker to bookmaker and between events. Horse races would have an over-round of 15-20% with most bookmakers, but some specialist markets would have over-rounds of more than 30%. Football matches would tend to be somewhere in between, depending upon the popularity of the match and the level of confidence that the bookmaker has in their prices.
The fiddly part is working it out yourself as it’s all about converting odds into implied probabilities and summing them up. Most punters haven’t got time for the maths, which is understandable enough. Luckily, comparison websites do it for you, pointing out which bookmaker offers the most generous book on any event.
That is where it becomes interesting though – the theoretical best book does not always mean the best odds on your specific option. One bookmaker can have the lowest total over-round but pay out less on the specific result that you desire. That is why serious punters use comparison tools to find the optimal price for their specific bet, rather than theoretical best book.
Exchanges tend to be better value than conventional bookmakers since they’re not adding the same profit margins. They generate profit through commission on winnings and not by tampering with odds, which can lead to more competitive prices in general.
Is it worthwhile to shop around to obtain the best book? Absolutely, if you bet a lot or with modest stakes. The margin between an over-round of 15% and an over-round of 25% may not be massive in one bet, but it makes a difference ultimately. It is similar to savings accounts – a few percentage difference may not make a difference for one savings transaction, but across a couple of hundred bets, it is the difference between winning and losing out in the long term.
Best book is simply about maximizing bang for your buck by finding bookmakers that are taking the least commission on the action.
