Super Bowl Betting – How the Bookies Lost

Great article from Bloomberg shows how the linemakers are reluctant to change the spread from where it’s set, even when they know its wrong.

Why, if the sportsbooks could see all the money flooding onto the Giants, did they simply not move the point spread? In financial markets, if all the money is short then the market will move down and if all the money is long then the market will move up.

The answer is that in sports betting, once the line has settled then the books will only move away from that point spread if there is major injury news. If Tom Brady had an injury so serious that he missed the game then the line might have moved from favoring the Patriots by 12 to favoring them by only 5, or perhaps less.

But if the line had been moved because of the weight of money, then the books may have found themselves taking early action on the Giants +12 and late action on the Patriots -9.
If the game then ended with the Patriots winning by 10 points they would have had to pay out to both sets of bettors, which would have been seriously expensive. In bookmaking terms this is known as getting ``middled'' and it is what linesmakers try to avoid doing, at almost any cost.