The Strength of Strength of Schedule

Kyle Rivas

From the FanPosts. Great stuff. -Joel

If someone tells you that "statistics never lie", they are probably about to lie to you by abusing statistics.

Nowhere is this more true than the NFL. Statistics are a terrible measuring device for the league, since the sample size is so incredibly small. Teams only play sixteen games each year, yet stats are thrown around about how such-and-such team has a player or unit that is "historically good." That doesn’t necessarily mean that they are the best; more likely they are just a statistical anomaly.

In sports like baseball, where each year 162 games are played and starting players typically receive hundreds of at-bats, statistics have become a crucial part of championship teams. The sample size is comparatively enormous, so statistics actually carry weight. This doesn’t translate to football… but we use statistics anyway. So since we’re resigned to using statistics, we might as well try to make them at least a little more accurate.

* * *

I’m hard pressed to remember a season where the strength of schedule stat has been thrown around more often. It is used to discredit the successes of both the Chiefs and our rivals, and has been used so much that it has essentially become meaningless.

There are several flaws with the typical strength of schedule statistics:

  • Included in the record of each team are games against the team you’re measuring. In other words, after Week 1, the Chiefs had played against a team that was one of the worst in the NFL- but only because they had played one game and lost. If you used a conventional strength of schedule metric after Week 1, you’d probably state the Chiefs record was inflated because the strength of the opponents they’d played so far was .000. See the problem? (On the other hand, we now realize that the Jaguars really are that bad.)
  • In a similar vein, a team’s poor record could be explained away as a byproduct of playing a bunch of strong teams. To continue the same example, Jaguars fans could say after Week 1, "We don’t have anything to be ashamed about; after all, we lost to an undefeated team."

Obviously, those are extreme examples. But as I said earlier, 16 games isn’t a very large sample. At this point, 8 weeks into the season, every one of the Chiefs’ opponents appears to be at least 12.5% weaker just because they played the Chiefs. We can counterbalance that rather easily- by taking the games against Kansas City completely out of the equation- but it still wouldn’t provide a truly accurate portrayal of strength of schedule. For that, we’ll have to go a little deeper, and look at who the Chiefs’ opponents have in turn played themselves.

In the following tables, I’m measuring whether or not the Chiefs’ opponents have been above or below average, and how substantial the difference is. What’s average? If a team was perfectly average, they would be expected to win games against below-.500 teams and lose games against above-.500 teams. Simple enough, right? (Yes, I could take this through multiple steps by comparing their opponents’ strength of schedule, but I’m not quite prepared to throw Occam’s razor completely out the window yet.)

Here are the records of the Chiefs’ opponents (not counting their game against KC) compared to how an average team would be expected to fare with the same schedule (expected record)*:

Chiefs Opponents Current Record Expected Record
Jacksonville 0-7 2-4*
Dallas 4-3 4-2*
Philadelphia 3-4 4-2*
NY Giants 2-5 5-2
Tennessee 3-3 2-4
Oakland 3-3 3-3
Houston 2-4 2-3*
Cleveland 3-4 4-3
TOTAL 20-33

*Games against .500 teams not included in expected record. An average team would win about 50% of their games against other average teams, meaning those games would not influence the expected win/loss total.

In total, Chiefs’ opponents have underperformed by about 8 wins, meaning the Chiefs’ schedule is about 15% weaker than an average NFL schedule. That shouldn’t be too surprising for Chiefs fans- we knew coming into the season we’d have a weak schedule, and we’ve played teams that have been doing surprisingly worse than we originally expected.

There’s another team that Chiefs fans might be interested in learning about.

Broncos Opponents Current Record Expected Record
NY Giants
Oakland 3-3
Philadelphia 3-4
Dallas 4-3 4-2
Jacksonville 0-7
Indianapolis 4-2
Washington 2-4
TOTAL 21-31

The opponents of the Broncos have underperformed by 9 wins, making their schedule 17% weaker than an average NFL schedule. It’s very similar to the Chiefs (especially when you consider the endless line of backup QBs KC has faced), but it turns out the Broncos’ schedule has been even easier than ours.


We’ll give this test a little more validity by throwing in a control team, which I arbitrarily decided on out of the few teams which hadn’t played anyone the Chiefs and Broncos had already played. I chose the Atlanta Falcons, who turn out to have a weaker schedule as well (5% weaker than the average) thanks to games against Tampa Bay and some of the weaker teams in the NFC West and AFC East. Maybe the Falcons are a little worse than I originally thought. I would have gone through all of the other 29 teams, but there is no way that I have time for that.

* * *

Beyond just wins and losses, the Chiefs have been accused of having a defense that is "historically good", while the Broncos have faced similar accusations of having a "historically good" offense. Once again, we must ask ourselves whether these units have actually played well on a "historical" level, or if this is once again a product of facing weaker teams.

Through half a season- by no means representative of the entire body of work these teams will go through- the answer for both teams is, "Yes, they are historically good." Through eight games, Chiefs’ opponents score about 8.0 points less when they play Kansas City. The Chiefs’ defense is allowing 40% less points than an average defense, a staggeringly high number. I’ve heard the Chiefs’ defense compared to the 2000 Ravens and 1985 Bears. Here’s how they measure up:

Average Points Prevented* Percentage Decrease
2013 Chiefs
8.0 40%
2000 Ravens
1985 Bears

*In other words, teams score 8.0 points less than usual when playing the 2013 Chiefs

Very similar numbers across the board. If the Chiefs can keep it up through the second half of the season, then we can consider their defense to be "historically" good. As for the Broncos’ offense…

If you’re a Chiefs fan looking for good news, I have none to give you. The Broncos score about 20 points more than their opponents usually give up, an improvement of a staggering 186%. This number is significantly better than the 2007 Patriots, and the 1999 Super Bowl Champion* Greatest Show on Turf Insert More Adjectives Here Rams:

Average Additional Points** Percentage Increase
2013 Broncos
19.8 186%
2007 Patriots
1999 Rams

*And yes, I chose the 1999 Rams as opposed to the 2000 iteration because the 1999 Rams actually won the Super Bowl. The point totals were similar enough, and the championship is what really matters.

**In other words, teams give up 19.8 points more than usual when playing the 2013 Broncos

* * *

We can all conclude that both the Chiefs and Broncos are extremely good football teams that have obliterated (well, almost obliterated) a relatively easy schedule. But that shouldn’t devalue the strengths of their defense and offense, respectively.

When you’re preparing for the Week 11 & 13 showdowns, here’s something interesting to keep in mind: the Chiefs allow 40% less points to opposing teams. Projected to the Broncos, we could expect Denver to score a little less than 24 points. The Broncos score 186% more points than opposing teams typically give up. Projected to the Chiefs, we could expect Denver to, again, score a little more than 24 points. These numbers are very close. The question that needs to be answered, then, is this. Can the Kansas City Chiefs score more than 24 points? If they can, they have a very good chance of winning against the Broncos.

Let's not look too far ahead though; we have a big game against a good Bills team coming up first.

This is a FanPost and does not necessarily reflect the views of Arrowhead Pride's writers or editors. It does reflect the views of this particular fan though, which is as important as the views of Arrowhead Pride writers or editors.