Bill James calls Sabermetrics "a search for objective knowledge about baseball." The same sort of idea is now being applied to football. A main contributor: Bill Barnwell of footballoutsiders.com. He told New York Newsday: "We use statistical analysis of game film to explore and ask questions about football that aren't asked. For every single play of the NFL season, we have someone watching that game and charting 15 or 20 different things that aren't included in the play-by play."
This week I caught up with Barnwell.
Q: Based on your analysis, rank the starting QBs in the NFC North with an explanation as to why you have them where you do.
A: I have to put Jay Cutler at the top; there's simply not very many quarterbacks who have produced at his level this early in their careers. There's no comparable quarterback perhaps in NFL history who was traded at the same point of their career after achieving the same level of success. He turned the ball over a few too many times last year, but that's what will happen when you're forced to throw all the time to catch up. His interception rate was flukily high and will regress back towards league average this year. Behind him would be Aaron Rodgers, albeit with the qualifier that he may very well have already peaked in his first season as a starter.
Third would be Mr. Favre, who didn't put up anyone's idea of a great season last year in New York while playing against one of the easiest schedule's any quarterback has gotten to face in the last 15 years. (He is joined among those 10 easiest schedules of pass defenses by AFC East compadres Chad Pennington and Trent Edwards, while Matt Cassel's slate was only slightly harder.) Well behind him would be Matthew Stafford.
Q: Same question with the defenses in the NFC North.
A: Have to put Minnesota #1 by a fair margin -- their -17.2% DVOA was fourth-best in the league last season. Chicago was second, with a -6.8% DVOA (seventh in the league); Green Bay was third, at 1.4%, while Detroit had the worst defense in the 15 years we have compiled DVOA for, at 29.2%.
I'd probably venture to guess that Chicago and Minnesota will be right near each other this year in a 1 and 1A sort of situation; Chicago had a lot of injuries last year, and injuries regress to the mean. Green Bay's 3-4 is a mess and will take some time to percolate, while Detroit's still looking to figure out where their building blocks are on defense.
For the uninitiated, DVOA is our core metric; it takes every play of the NFL season and compares a team's performance to how a league-average team would have done, and then adjusts for the down and distance, the game situation, and the quality of the opposition. The result is a percentage; since defenses want to allow less than the league average, when we say that the Vikings' defense had a -17.2% DVOA, it means that they were 17.2% better than league average.
Q: Considering the research you've compiled on the Vikings, including extensive film breakdown sessions, give us some out-of-the-box, unconventional takes? In other words, stuff the average or even die-hard fan would not realize.
A: One thing that I always talk about with the Vikings is the yards Bernard Berrian lost on pass interference penalties. Last year, Berrian drew six pass interference penalties for 127 yards; if you factor in those yards (and there's no reason not to, since the offense picks them up and the interference, by the letter of the law, prevented Berrian from making a catch), Berrian's receiving yards go from 964 to 1091. It sure makes his 2008 season look a lot better.
Q: According to your numbers, Visanthe Shiancoe was the No. 2 TE in football last year...explain how you came to that conclusion, and can he get better?
A: We also use that DVOA statistic for individual players when they're thrown passes or carry the ball. We compare their performance to the average performance of a player at that position after adjusting for down, distance, situation, and the quality of the opponent.
In this case, Shiancoe's 50% DVOA means that he was 50% better than a league-average player on those plays in which he was thrown the ball. Of course, DVOA doesn't know who was in coverage, or whether the safeties that would normally worry about Shiancoe were bugging out about AD in the backfield.
That's why I wouldn't say that Shiancoe was the second-best tight end in football a year ago. Shiancoe's second-place rank in DVOA means that he was the second best receiving tight end in the league on the passes he was thrown in the context of the Vikings offense. I strongly doubt he'll improve; his huge DVOA figure and touchdown total is totally out of line with his previous performance, which almost always means that the player will regress some in the subsequent season. I still think he's a valuable player, but he's not going to put up a crazy DVOA like that again.
Q: A headline from your site: Trending down: QB Brett Favre -- Why?
A: As mentioned above, Favre had a pretty mundane season despite playing a ridiculously easy schedule. He also had a very good offensive line that made it to 80 starts around him, so the doubling of his sack rate is concerning. His injured rotator cuff is also concerning; he's been incredibly sturdy throughout his career, but he's 40 now. It's a lot easier to get hurt at 40, even if you're a physical ironman.
Q: The Vikings' most overrated player is? And underrated?
A: Geez. That's a tough one. Maybe Bobby Wade for most overrated? I'm not really sure why he has a job and not 15 or 20 other receivers who can do exactly what he does for the league minimum.
I would have said Antoine Winfield for underrated, but he finally (deservedly) made it to the Pro Bowl last year, so I won't pick him. Maybe Kevin Williams -- I think people realize that he's very good, but most people don't realize what an absolute force of nature he can be in the middle, even as a pass rusher. He's still young, obviously, but he's several years into a Hall of Fame career at this point.
Q: From the naked eye, the Bears defense was terrible last year, but your numbers indicate otherwise...please explain and what do you expect from maybe the Vikings' No. 1 nemesis in the North?
A: I would suggest that the naked eye probably isn't the best tool for analyzing how 11 players perform over a thousand snaps or so.
I don't even think you could say they were terrible from any perspective. They gave up 350 points last year, which was 16th in the league, so their scoring defense was right around league average.
Then, of course, you have to consider the context. Namely, it's the fact that they faced 201 drives last year (not include "drives" that were kneeldowns at the end of a half); only one other team (Philadelphia) faced as many as 195. The league average was 176, so Chicago faced 25 more drives than the average team.
Divide the points they gave up by the number of drives they faced, and Chicago only gave up 1.68 points per drive; that was ninth in the league, which is far better than 16th and closer to our seventh-overall ranking. They didn't get much help from their offense or special teams coverage, as the average drive Chicago faced started from the 31-yard line, which was eighth-worst in the league. (Minnesota was actually seventh-worst, and you can probably figure out why.)
Their 2009 performance depends on health and the pass rush. They couldn't rush the passer with their front four last year, so Lovie Smith had to blitz more frequently and mix up his looks defensively; the result was a decline in their performance, and when the secondary started going down with injuries, they were basically hanging on for dear life. If the secondary stays healthy and they can actually generate a pass rush up front, the defense could be very, very good -- right up there with Pittsburgh and Baltimore.
Q: Green Bay is switching to a 3-4 defense, although word is, it won't be 100 percent 3-4 dominated, but will its defense improve enough?...And do you buy on the idea that QB Aaron Rodgers is ready to explode for a super year after his phenomenal preseason?
A: Easy question first: Throw out preseason stats for players. Almost entirely useless, and absolutely useless when you're considering veteran players.
The short answer about Green Bay's 3-4 is that we don't know yet. It depends on how well the players they're moving around adapt to their new roles. Past scheme switches in the league have shown that teams switching to a 3-4 from a 4-3 tend to struggle with the switch over the first four games before settling in and improving on their previous level of performance, but the variance with an individual team as opposed to the "average" switch can be vicious. Again, it's a health thing; that secondary's going to need to stay healthy for the Packers to be able to go through growing pains up front. If Al Harris and Charles Woodson age quickly â¦ look out.
Q: Give us a team or two that we expect very little from (like last year with Atlanta and to a degree Baltimore) that has a very good chance to be in the mix for a playoff spot?
A: Our pick for this season was St. Louis, although that might be up in the air now that Adam Carriker is out for the year. Our projection system compares the moves that they made to how other teams have built their teams in the past, and compares the splits from their 2008 season to previous teams' campaigns, and sees them improving by a fair amount in a weak division. We're also projecting Jacksonville to return to prominence, thanks to a much-improved (and much-healthier) offensive line.
Q: What do you say to the individuals who disagree that you can really assign win probabilities in a game like football where so much is due to chemistry, injuries, and luck?
A: I don't think it's a binary decision; it's not "Statistics can't be applied to football" or "Statistics can be applied perfectly to football". What we do is focus on the process, understanding that the nature of a 16-game schedule or the bounces of a ball on a single play can have a huge impact. Our goal is to build models that work over 15 seasons of team performance and serve as better predictors of team performance. DVOA is a better predictor of a team's win-loss record in the subsequent season than any other statistic, including the team's record in the previous year.
Our statistics will never be perfect; no statistical model ever is. There's plenty of research we do into the game and why teams win, though, that's fascinating and counterintuitive while remaining demonstrably true. The work we do is certainly good enough to deserve the attention it's received, even though there's still much more to be done.