As virtually every professional bettor will tell you, backing heavy favourites is a sure fire way to the poorhouse. That is common knowledge, right? Perhaps, but there is one problem with that type of thinking: it’s dead wrong.

The received wisdom will be the linesmakers skew their odds on heavy favourites because the public love betting on the very best teams. The bookies undoubtedly see a flurry of parlays involving clubs like Chelsea, Barcelona and Juventus every weekend. Surely there’s value in taking the underdog in these situations, is not there?

The truth is, numerous studies have shown that blindly backing long shots is a losing proposition within the long term. To view why that is the situation, we have to discover how a bookmaker operates. Since the bookies take most of their action on short-priced favourites, it’s often assumed they are exposed to big liabilities if all the hot teams win. Although this is sometimes the case, and many bookmakers suffer months of huge losses, there are actually several ways a bookie can protect himself.

It’s important to keep in mind most heavy favourites are combined in parlays involving at least three teams. A bookmaker only needs one loser to take his customer’s money. Consequently, there is little need to lower the odds on a “public” team. Many sportsbooks will even inflate the odds of a hot favourite to attract new customers, safe within the knowledge that parlay players will not hurt their bottom line.

Should the favourite’s odds are an accurate reflection of it’s true probability of winning, the bookmaker must make adjustments elsewhere. That usually means offering worse odds on the underdog and the draw. Knowing the concept of theoretical hold may make this clearer.

When making lines, a sportsbook will offer odds on each team which provide it a slight edge, ensuring a profit regardless of how the game turns out. This really is called the Theoretical Hold and is expressed as a percentage. It represents the combined amount of customers’ bets that the bookmaker expects to keep.

It’s called theoretical because in reality a bookmaker rarely has balanced action on all sides. If a bookie takes the bulk of his bets on a heavy favourite, quality online football gambling he can offer it at a more generous price and accept a smaller profit margin. Short-priced favourites generally have small margins, but high volumes. Bigger odds mean bigger margins. There is little incentive for a bookie to offer competitive odds on a big underdog if he will not expect much betting interest in that team.