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

The received wisdom is the linesmakers skew their odds on heavy favourites since the public love betting on the most effective teams. The bookies without doubt see a flurry of parlays involving clubs like Chelsea, Barcelona and Juventus every weekend. Surely there is value in taking the underdog in these situations, isn’t there?

In reality, numerous research has shown that blindly backing long shots is a losing proposition in the long-term. To determine why that is the situation, we have to know how a bookmaker operates. Considering that the bookies take most of their action on short-priced favourites, it’s often assumed they can be exposed to big liabilities if all of the hot teams win. While this is sometimes the situation, and lots of bookmakers suffer months of huge losses, you can find several ways a bookie can protect himself.

You need 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. So, 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, best online casino safe within the knowledge that parlay players won’t hurt their bottom line.

In the event 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 as well as the draw. Knowing the concept of theoretical hold may make this clearer.

When creating 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 portion. 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, 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’s little incentive for a bookie to offer competitive odds on a big underdog if he doesn’t expect much betting interest in that team.