You probably were not paying much attention in that 10th grade geometry class when we learned all those math formulas. But one formula was drilled into our heads and is hard to forget — the Pythagorean theorem, or A2 + B2 = C2.
Bill James used the Pythagorean theorem many years ago to indicate a baseball team’s future performance based on runs scored and allowed as they correlate to winning percentage. From there a formula was created to apply it to the NFL.
I am unsure who created the NFL formula, but Football Outsiders has given it some research as a way to predict a team’s outcomes based on its prior-year performance. I have used this for 12 years or so to help gauge NFL season win totals. Though it’s only one piece of the puzzle, some lessons can be learned to set us up in the right direction on season win totals.
An example from the 2019 season: The Green Bay Packers went 13-3, scoring 376 points and allowing 313. The Pythagorean theorem suggests the Packers should have won just 9.7 games and lost 6.3. In other words, they won 3.3 more games than they should have based on this formula.
If a team overachieved regular-season wins by two or more games the year before, we look to go Under its season win total the next season. Since 2007, there have been 22 such teams. By fading those 22 teams to the Under season win total the next season, you would have gone 18-3-1. Of those 22 teams, 18 won at least three fewer games the next season than they won the previous season, including all eight teams that won 13 or more.
There have been 26 teams since 2007 that won at least two games fewer than their Pythagorean numbers suggest they should have won. Those 26 teams went 16-9-1 the next season versus their season win total.
Between the two situations, you would have gone 34-12-2 following these Pythagorean plays. Eight such plays apply this year. Here are the best three:
Packers Under 9: Besides being incredibly lucky last year by going 6-1 SU in games decided by seven points or fewer, Green Bay also lost RT Bryan Bulaga and LB Blake Martinez in free agency. The schedule will do the Packers no favors. Their own division had three teams at .500 or better, and Detroit figures to be better with Matthew Stafford healthy all year. The Packers face the other No. 1 teams from the NFC (49ers, Saints, Eagles). They face an AFC South with three teams capable of finishing .500 or better. And they meet improved Tampa Bay.
Saints Under 10¹/₂: The Saints have won their division three straight years and have won 13 games each of the past two seasons. But last year they won just three games against teams that finished above .500. This year they will play all but two games against teams with season win totals of seven or higher. And they went 6-1 SU in games decided by seven or fewer points, so they will need to continue to be incredibly fortunate in close games to get over their season win total. Tampa Bay figures to be much tougher with the addition of Tom Brady and Rob Gronkowski. The Saints will also face first-place teams in San Francisco, Green Bay and Philadelphia in addition to defending Super Bowl champion Kansas City.
Cowboys Over 10: Mike McCarthy takes over for Jason Garrett as Dallas’ coach. Though McCarthy faced plenty of criticism at the end of his run in Green Bay, he has always been a particularly good quarterbacks coach and used his one-year hiatus to retool his offensive scheme. The Cowboys won eight games last year despite going 0-5 SU in games decided by seven points or fewer. They play five games against teams predicted to win fewer than seven games. They were just 2-7 SU in games against teams finishing .500 or above last year. That includes going 0-4 SU in games decided by seven or fewer points. Those close losses have a way of evening out from year to year. If they do that, the Cowboys have a chance to go over their season win total.
Scott Yellen, a professional sports bettor, wrote this piece for VSiN’s 2020 Pro Football Betting Guide, a 104-page digital magazine available for download at VSiN.com/subscribe.