Weighted Yards: The new way to measure an NFL offense.

            How should we measure the success of an NFL offense? Yards and points are the two most common measures but they don’t tell the whole story, not even close. If two teams are playing in the wild card round of the playoffs and they each averaged 320 yards and 24 points for the season, are they evenly matched offenses? According to these two stats alone they are; but we don’t know anything about what the team went through to come to these numbers. That’s why I propose we start tracking weighted yards. Weighted yards will cut through the mystery and explain how many yards these teams DESERVED to finish the season with. How? Strength of schedule.

            Just one month ago the NFL Network had a show in which they released the schedules of all 32 NFL teams. Every football fan in the country seemed to be interested and all we heard about for the next 2 days was what teams had the hardest and easiest schedules. And then what? Nobody cares about strength of schedule until, well, until next year’s schedule release show. This is understandable; strength of schedule in the offseason really means nothing because teams that look good in September could be out of it in December and teams that look like contenders in August could be out of it by November. But strength of schedule in the regular season, which no one talks about, means a ton.

            Let’s pretend that the Falcons and Steelers were to matchup in the Superbowl last season (The Giants, the Broncos, and other 8 teams that made the playoffs had something better to do in this fictional world). The Falcons averaged 376.6 yards per game in the regular season while the Steelers averaged 372.3. So conventional wisdom would indicate that the Falcons had a slightly better offense, but how did they get here. We need to look at the strength of the defenses these teams played. To make this easier I have taken each team’s total yardage and turned it into a decimal, for example the league average in yards allowed per game is 347 so if a team allowed 173.5 yards per game they allowed .5 or half of the league average. Any number higher than one indicates that the team allowed above the league average in yards per game. The Falcons schedule looked like this:

Chicago	1.0103
Philadelphia	0.9368
Tampa Bay	1.1371
Seattle	0.9578
Green Bay	1.1867
Carolina	1.0887
Detroit	1.0599
BYE
Indianapolis	1.0694
New Orleans	1.0622
Tennessee	1.0238
Minnesota	1.0328
Houston	0.8237
Carolina	1.0887
Jacksonville	0.9024
New Orleans	1.0622
Tampa Bay	1.1371
AVG	1.036229

This may look confusing but when you average all these numbers out it means that the defenses the Falcons faced allowed, on average, 3.6% more yards per game than the average defense. This means that although the Falcons gained 376.6 yards per game, against an average defense they would be expected to gain only 362.9 yards per game. The Steelers schedule breaks down like this:

Baltimore	0.8330
Seattle	0.9578
Indianapolis	1.0694
Houston	0.8237
Tennessee	1.0238
Jacksonville	0.9024
Arizona	1.0238
New England	1.1853
Baltimore	0.8330
Cincinatti	0.9117
BYE
Kansas City	0.9610
Cincinatti	0.9117
Cleveland	0.9584
San Francisco	0.8886
St Louis	1.0333
Cleveland	0.9584
AVG	0.9547

This means that the defenses the Steelers faced allowed, on average, 4.5% less yards per game than the average defense. Had the Steelers faced an average defense they would be expected to gain 389.2 yards per game instead of the 372.3 that they gained against their much tougher schedule.

            So at initial glance these offenses are very similar with a slight edge going to the Falcons, but when we actually take into account how these numbers were earned it becomes clear that the Steelers were much better than their numbers would indicate and the Falcons weren’t quite as good. Now the numbers say that the Steelers gained 389.2 yards per game compared to the Falcons 362.9. This is a difference of 30 yards from what conventional stats would tell us, and any football fan knows that in a game of inches 30 yards can be as good as a mile.

            The basis of these stats can also be used to predict defensive performance by using the same calculations. They can also be used to predict how teams may fare against each other but I will get into that in a separate article, for now just remember that when two teams play each other yardage doesn’t tell the whole story.