A new week of Power Rankings brings about a new feature: Defensive Adjusted Rankings. I'll still be presenting the Non-Adjusted raw rankings, but I think the Adjusted Rankings are a more accurate picture of what is going on in the league. Here's how I did it:
- First off, a big thank you to Neil Paine over at Pro-Football-Reference.com, who pointed me to a 5 minute video tutorial on Excel Iterations. I was struggling mightily with it, and I only got it to work with his help. Make sure you check out the PFR blog for even more football-related information.
- I took the average of all games for each team, and I subtracted out the historic average for each stat, so I now have either a plus or minus number for each team. I did this both on offense and defense.
- I then found what the average of each team played against, so I could see the level of teams played against. For example, with DSR, the Colts are 9.3% above average, but opposing defenses they've faced are 4% below average, so I'd start with an adjusted average of 5.3% above average.
- Now's the tricky part...since the Colts now have a new figure, it changes each of the defenses they have faced, which would then change the offensive adjustements, etc. This is where the Excel Iterations come in. Eventually, the numbers slowly converge until they don't change any more, which are the final adjusted numbers, that are above/below the historic average. Just add that back in and you're good to go.
- I ranked the new adjusted numbers the same way as before, and (I think) you have a more accurate representation of the team's strengths.
- If you want another explanation, here's where I got the idea: PFR.com Simple Ranking System.
Now that you are all thoroughly confused, how about I just show you the results:
Here's the Power Rankings (click on a column header to sort):
- The Colts moved up to #3 in the Non-Adjusted Rankings, but fell to #5 in the Adjusted Rankings. Why you may ask? The defense is severely hurt when adjusting for the opposing offenses they have faced, dropping from #12 to #23! Looking at the teams they've faced, you can see why: The Dolphins are the best team they've faced, and they are #10, and next is Jacksonville at #17! If the defense can continue playing well (which they have been) the next 4 weeks, that number is going to shoot up.
- The biggest movers up when adjusting for defense are the Bengals and Dolphins, who each move up 7 spots. Biggest losers? Eagles and Steelers, who dropped 8 and 7 spots, respectively. I agree with all four of those movements, as you should as well.
- Even though the Packers have lost to the Vikings twice, they're ranked higher than the Vikings. I'm guessing everyone's favorite 40 year old QB has something to do with those 2 games.
- The Jaguars have the worst defense in the league. Anyone want to disagree after what the Titans did to them last week?
Here's the Strength of Schedule:
|Team||Strength of Schedule|
A couple things here:
- There is definitely some merit to saying the Colts have played an easy schedule, because they clearly have. The defense has faced the 3rd easiest schedule. But look who has had an easier defensive schedule? Week 9 opponent Houston, who has played the easiest defensive schedule in the league. I think they'll finally be tested this week.
- Who is playing the 1st place schedule in the AFC North? The Browns, Ravens, and Bengals are in the top 5 of SoS, while the Steelers are 24th.
I'm going to be working on 2 more improvements that should be done before the end of the season:
- Future Strength of Schedule. Should be done for next week.
- Weighted Rankings. This means that more recent games will count more than older games, as it tells a better story of how the team is playing now, rather than (possibly) 3 months ago. Give me a couple weeks on this to set it all up, but I think it's necessary for the best rankings.