As we gear up for another NFL season kicking off in just over a week, there will be lots of discussion of Super Bowl contenders and playoff predictions. Which teams will improve and which will decline. One of the big and often over-looked factors in these exercises is a team’s strength of schedule.
Often, when the schedule is released, you’ll see attempts at determining the most difficult schedules like this one that use the previous season’s records to determine the quality of the opponent for each game. While this is a reasonable starting point, it definitely has its flaws.
What’s wrong with traditional Strength of Schedule measures?
Two main factors, one obvious and one maybe not so obvious, are at play here. First, on the obvious front, teams change from year to year. The Broncos added Peyton Manning. The Chiefs get Jamaal Charles back from injury. The Ravens lost Terrell Suggs, likely for the season. All of these major and minor changes affect the quality of a team from last year to the current year.
The first flaw deals with team quality changing from season to season, but the second flaw is that last season’s winning percentage isn’t even an accurate measure of last season’s team quality. You have your traditional under- (ex. Eagles) and over-performers (ex. Broncos), but you also have simple regression to the mean where the teams with the worst record weren’t actually as bad as their record indicates and vice versa for the teams with the best records. The Colts and Rams were definitely two of the worst teams, just not 2-14 bad. And the Packers were a juggernaut but they aren’t going to win 15 out of every 16 games they play in the long run.
A better way
So where can we find a more accurate measure of a team’s strength for the upcoming season? Well, luckily for us, there’s someone who specializes in that: Vegas. Every year, the sportsbooks put out over/under win totals for every NFL team. Here’s a comparison of this year’s over/under win totals compared to last season’s wins (NOTE: Most win totals were taken from PinnacleSports.com. The Dolphins were not listed and so I looked at a few other sources that were all around 7 wins.):
| Team | Vegas | 2011 | Diff |
|---|---|---|---|
| STL | 6 | 2 | 4 |
| IND | 5.5 | 2 | 3.5 |
| MIN | 6 | 3 | 3 |
| TB | 6 | 4 | 2 |
| PHI | 10 | 8 | 2 |
| WAS | 6.5 | 5 | 1.5 |
| BUF | 7.5 | 6 | 1.5 |
| CAR | 7.5 | 6 | 1.5 |
| CHI | 9.5 | 8 | 1.5 |
| CLE | 5.5 | 4 | 1.5 |
| KC | 8 | 7 | 1 |
| MIA | 7 | 6 | 1 |
| SD | 9 | 8 | 1 |
| NYG | 9.5 | 9 | 0.5 |
| NYJ | 8.5 | 8 | 0.5 |
| JAC | 5.5 | 5 | 0.5 |
| DAL | 8.5 | 8 | 0.5 |
| DEN | 8.5 | 8 | 0.5 |
| SEA | 7 | 7 | 0 |
| HOU | 10 | 10 | 0 |
| DET | 9.5 | 10 | -0.5 |
| CIN | 8.5 | 9 | -0.5 |
| ARI | 7 | 8 | -1 |
| ATL | 9 | 10 | -1 |
| NE | 12 | 13 | -1 |
| OAK | 7 | 8 | -1 |
| PIT | 10 | 12 | -2 |
| TEN | 7 | 9 | -2 |
| BAL | 10 | 12 | -2 |
| NO | 10 | 13 | -3 |
| GB | 12 | 15 | -3 |
| SF | 10 | 13 | -3 |
Here we have some teams on each end of the spectrum that Vegas expects to regress a bit back towards .500 such as the Rams, Colts, and Vikings on the low end and the Packers, 49ers, and Saints on the other. You also have teams like the Titans who overachieved last year. Using last season’s record paints them in too favorable a light as they were likely a bit lucky with their win-loss record. The Eagles, conversely, were a much better team than their 8-8 record indicated in 2011 and Vegas’s projections reflect that.
Now, Vegas lines have their own flaws. For one, the win total listed has odds. For instance, the Bengals and Cowboys are both listed at 8.5 wins but the odds favor the Cowboys going over and the Bengals going under meaning Vegas thinks Dallas is better but I treated them as the same. I did not account for this in my quick look, though one could. Also, schedule itself is also a factor here, creating a kind of circular reference where a team’s record depends on its strength of schedule which depends on opponents records which depend on their schedules, and so on and so forth. This measure is definitely not perfect, but the flaws are much smaller compared to the traditional method.
Improved SOS
So with our new and improved way to measure the quality of each team’s opponents, let’s look at who has the hardest and easiest schedule heading into the 2012 season, with the traditional method added in there for comparison.
| Team | Vegas SOS | Vegas Rk | 2011 SOS | 2011 Rk |
|---|---|---|---|---|
| NYG | 0.541 | 1 | 0.547 | 1 |
| CLE | 0.535 | 2 | 0.527 | 3 |
| BAL | 0.535 | 2 | 0.524 | 5 |
| ARI | 0.535 | 2 | 0.512 | 8 |
| DEN | 0.533 | 5 | 0.543 | 2 |
| DAL | 0.527 | 6 | 0.504 | 11 |
| WAS | 0.525 | 7 | 0.488 | 25 |
| SEA | 0.523 | 8 | 0.504 | 12 |
| NO | 0.523 | 8 | 0.504 | 12 |
| CAR | 0.521 | 10 | 0.508 | 10 |
| TEN | 0.520 | 11 | 0.481 | 28 |
| JAC | 0.518 | 12 | 0.500 | 15 |
| STL | 0.518 | 12 | 0.524 | 4 |
| MIN | 0.518 | 12 | 0.512 | 8 |
| PHI | 0.516 | 15 | 0.516 | 7 |
| TB | 0.516 | 15 | 0.485 | 27 |
| DET | 0.516 | 15 | 0.492 | 20 |
| SF | 0.514 | 18 | 0.488 | 24 |
| ATL | 0.510 | 19 | 0.488 | 25 |
| PIT | 0.510 | 19 | 0.500 | 16 |
| CIN | 0.510 | 19 | 0.500 | 17 |
| IND | 0.510 | 19 | 0.500 | 14 |
| NYJ | 0.508 | 23 | 0.492 | 22 |
| OAK | 0.508 | 23 | 0.496 | 19 |
| MIA | 0.506 | 25 | 0.496 | 18 |
| SD | 0.504 | 26 | 0.520 | 6 |
| CHI | 0.504 | 26 | 0.492 | 21 |
| KC | 0.502 | 28 | 0.492 | 23 |
| GB | 0.498 | 29 | 0.469 | 31 |
| HOU | 0.494 | 30 | 0.473 | 29 |
| BUF | 0.494 | 30 | 0.473 | 29 |
| NE | 0.479 | 32 | 0.453 | 32 |
The Giants still have the most difficult schedule with a tough division, games against the Packers and 49ers for winning their division last year, and a tough AFC North draw. New England remains at the bottom with the easiest schedule as their division is relatively weak (remember, they don’t have to play themselves) and they drew the weak AFC South and NFC West.
However, some teams definitely look different. Tennessee goes from the 28th-hardest schedule to the 11th thanks to games against bottom-dwellers expected to improve some (IND (x2), MIN, BUF, MIA) and also some middle of the pack teams that should be a little better like SD, CHI, and NYJ. San Diego’s schedule looks easier, conversely, as NO, BAL, PIT, TEN, and OAK (x2) are all a bit overrated by their 2011 records.
Conclusion
By doing a little extra work, we can get a much clearer picture of what we’re looking for. Vegas win totals are designed exactly for what we’re looking for in measuring strength of schedule. You could also use other pre-season projection systems such as these by TeamRankings.com or any other site. These should give a more accurate representation of team quality heading into this season than last year’s record can provide.
Now that you know what really lies ahead for your favorite team, you can be more optimistic (or pessimistic) about their chances of playing into January. Of course, a lot will happen in the meantime. Until then, enjoy the ride.