There are two key numbers in football betting. It doesn't take a rocket scientist to figure out those numbers are three and seven.
Since so many games -- especially NFL games -- are decided by these two numbers, bookmakers are very aware of them. If they open a game at 7.5 and it goes to 6.5, they open themselves up to a huge loss. That's because the people that took the dog at +7.5 have a good chance to win and the people that took the favorite at -6.5 do as well. Heck, a lot of times these are the same people, going for what is known as a "middle."
So when a book moves a line off of seven, we know there is something going on. It's such a dangerous, scary, risky move that it's rarely done. And this week, we see it in the Ravens at Seahawks game.
This game opened at Ravens -7 almost everywhere. Predictably, most of the public money has come in on the Seahawks. However, the line is now Ravens -6.5.
We can draw two conclusions from this: 1) There is a lot of very sharp, professional money coming in on the Seahawks. 2) We can go for a middle.
If we shop around, we can still get Seahawks +7 in some spots. Maybe by Sunday we can get +7.5. But right now, we can get Ravens -6.5 By taking both sides, we risk almost nothing and get to go for a big payday.