It’s been quite a year for the double-digit underdogs in the NFL. Heading into the weekend underdogs were a perfect 9-0 against the spread, but they finally broke through with a point-spread cover (Seattle +10½ at Tampa Bay) and a near-miss with the 49ers at the New York Giants – early bettors (at +10½ ) lost while those who waited (+12½ ) cashed tickets.
Nonetheless, double-digit NFL dogs have still covered at an amazing 90.1 percent clip.
Equally amazing is the success rate of favorites who lay just a couple of points less (between 7½ points and 9½ points). So far, these favorites are 11-8 against the spread (ATS), for a decent 57.9 percent win rate.
The first two weeks of this season saw this double-digit trend start with the Chiefs covering as 16-point underdogs at the Pats (NE 17-10) and the Bears getting the money as a 10½-point dog at the Colts (Bears 29-13) in Week 1 followed by the Raiders (+10) covering at the Bills (Buffalo 24-23) in Week 2.
Week 3 saw two more big numbers fail to cover when the Giants (-13) only beat the Bengals, 26-23, and the Patriots, a 12½-point favorite, getting beat outright by the Dolphins, 38-13.
The Redskins (+400 Moneyline), a 10-point underdog to the Cowboys, also won outright in Week 4, 26-24. Then in Week 5, Dallas again fell as a big double-digit favorite (-16) to the Bengals as 16-point chalks (Cowboys 31-22).
Last weekend, the trend jumped to 9-0 ATS when the 13-point favorite Vikings eked out a last-minute win over the Lions (12-10), and the Redskins, an 11½-point favorite, were upset by the then undefeated Rams, 19-17.
One guy all over the trends is GamingToday columnist Andy Iskoe, whose records revealed that over the past six years (2002-2008), there have been 177 instances in the NFL where teams closed as 10-point favorites (Las Vegas Hilton SuperBook).
In those 177 games, Iskoe said the underdog had covered 93 times (52.5%), the favorite 80 times (45%) and four of the games pushed (2.3%).
Iskoe – who said a lot of professional gamblers will automatically plug in a double-digit dog and just bet them on this mega-trend – said that he wouldn’t be surprised if the double-digit favorites didn’t start doing a little covering of their own and revert back to that statistical mean.
The so-called "regression to the mean" hypothesis suggests everything evens out in the long run: coin flips, dice rolls and, apparently, double-digit favorites.
Only time will tell.