The beginning of the football season can be the most frustrating time of the year for sports bettors — it’s the time when they know the least about the NFL. But Vegas doesn’t know much, either, potentially leading to betting lines and odds that don’t make sense, if you, the savvy sports gambler, just know where to look. On the latest Deep Coverage podcast, Kevin Clark talked to Justin Davis and Andy Fodor, two professors at Ohio University, who have examined NFL betting patterns and have identified several inconsistencies in early-season sports betting. So what does history tell us about the odds this weekend? Just look at the patterns Davis and Fodor discovered — though there are no guarantees these bets can make you rich quick.
Listen to the full podcast here. This transcript has been edited and condensed.
Underdogs Facing Playoff Teams in Week 1 Tend to Be Underestimated
Kevin Clark: [Andy Fodor and Justin Davis] examined over 2,000 games from 2004 to 2012 in the regular season. But once the data was narrowed down, they focused on Week 1, and they found something stunning.
Andy Fodor: The lines are wrong.
K.C.: The researchers discovered a pattern where teams that made the playoffs in the prior season were consistently favored by too much the opening week the following season. When those teams were matched up with non-playoff opponents in Week 1, it would have been financially in your favor to put the money on the underdog. So much so, that on average it yielded a return of 22.6 percent.
Justin Davis: Of course we went back and double- and triple-checked it, because we couldn’t find any study that came even remotely close to a finding that strong.
K.C.: There are some [bets this week] that seem like long shots. Picking the awful Tennessee Titans to beat the solid Minnesota Vikings. But others seem downright insane: You’d have to pick the Jacksonville Jaguars to cover against the perennial Super Bowl–contending Green Bay Packers. This, on the surface, seems crazy, but not when you look at the data.
Every non-playoff NFL team facing a playoff participant in Week 1 as an underdog (odds via Vegas Insider):
- Titans (+2.5) vs. Vikings
- Jets (+2.5) vs. Bengals
- Chargers (+6.5) at Chiefs
- Bears (+6) at Texans
- Jaguars (+5.5) vs. Packers
- Dolphins (+10.5) at Seahawks
Vegas Overestimates How Many Points Will Be Scored in the First Week
K.C.: In 2014, the group published a paper titled “Early Season NFL Over/Under Bias,” looking only at bets on the combined total score of a game, known as the over/under. Over a period of 10 years, from 2000 to 2010, if you simply bet under on every game in Week 1, you’d get a return of 13.6 percent in profit. In gambling, an arena where anything over breaking even is considered great, this is remarkable. This is another example of where bookmakers got it wrong: The oddsmakers adjusted gambling lines slightly, because everyone knows that NFL offenses take a few weeks to get into their usual form. But these guys found that Vegas didn’t adjust nearly enough.
A.F.: The total average difference [in over/under lines] from Week 1 to the rest of the season was about 0.4 points, when in reality, [teams are] actually performing at about 3.4 points less in Week 1. So that’s a three-point gap there that’s unaccounted for by oddsmakers in that first week.
When Two 0–1 Teams Collide in Week 2, the Underdog Is Likely Underestimated
K.C.: The following year, they discovered another inefficiency, this time relating to Week 2 of the season. There are a slew of wonky facts about Week 2 betting. After all, the only evidence we have to go on is Week 1, making it almost as difficult to predict as that week.
J.D.: In Week 2, if you have two teams that both lost in Week 1, then still, the underdog is going to be heavily undervalued, to the point of they actually cover the spread just over 70 percent of the time.
K.C.: Now 70 percent sounds like a huge number — some may even call it a lock, and that may be. But before you call your bookie or hop in the car to Vegas, remember: This is not a way to get rich quick. This partly explains why holes like the ones pointed out in the study can continue to exist. Casual gamblers are exactly that: casual. They take things week by week and rarely care about the bigger picture, like the stuff in this study.
J.D.: If you are looking to take advantage of market efficiencies, it’s not a short-term game. That would be the same thing as going out and buying stock in a company and expecting you’re going to get a big return tomorrow. If you’re confident in the result, if you have done your due diligence, you have to be in there for the long run, and in the long run, it should pay off.