Writers of Pro Football Prospectus 2008

07 Nov 2007

It Isn't All Norv's Fault

No, this is not a link to some wacko writer trying to drum up controversy to fuel talk radio. This is a long-form extra point where I argue that laying the blame for the Chargers struggles solely at the feet of Norv Turner is unfair.

I think I can safely say that nobody on the staff here at Football Outsiders thinks that Norv Turner was a good choice to be the head coach of the Chargers. Still, the Chargers' struggles this season are too easily being explained solely based on the change in head coaches. The simple truth is that teams that win 14 games, as the Chargers did last year, are likely to regress the next season no matter who is coach.

Last year, three teams won at least 13 games: San Diego, Baltimore, and Chicago. Two kept their head coach. This year, the three teams are a combined 11-13, and not one has a winning record. They rank 13th, 20th, and 27th respectively in DVOA. Norv's team, by the way, ranks the highest.

Between 1996 and 2005, nine teams won 14 games. The next season, they averaged nine wins per team. Only three teams won more than 10 games (2003 Patriots, 2005 Steelers, and 2006 Colts). The Chargers were far from assured of continued dominance had Schottenheimer remained.

Furthermore, the Chargers have hardly been a consistent juggernaut under Marty. Just two years ago, they were 9-7. In Marty's five years in San Diego, they only made the playoffs two times.

The Chargers played the third easiest schedule of opposing teams last season. Counting the playoffs, they were 0-2 against the only two teams they played who finished the season in the top 10 in DVOA. This year, they are 0-3 against teams currently in the top 10 in DVOA. They are 4-1 against non top-10 teams with all their wins coming by double digits. This is clearly a team capable of pounding inferior opponents.

Also, the Chargers were clearly showing some downward trends at the end of last season, at least in their passing game. In the season's final six games, Rivers completed less than 50 percent of his passes three times including woeful performances against Kansas City and Seattle. Through 10 games, he had 15 touchdowns and 5 interceptions. The final six games, he had 7 touchdowns and 5 interceptions. Norv Turner's job is to fix that, but it seems far from certain that Rivers would be lighting up opposing defenses if Schottenheimer was still coach, particularly with two new starting receivers.

Obviously, I've cherry-picked stats to some extent numbers to help state my case. Furthermore, I think firing Marty was a dumb decision and hiring Turner was even worse. Still, the Chargers were due to come back to earth this season for a number of reasons. To lay all the blame on coaching changes is way too simplistic. They may limp into the playoffs with a 9-7 record, but were Marty still their coach, I'd be shocked if they were better than 11-5 and would bet that they would finish 10-6.

Posted by: Ned Macey on 07 Nov 2007

45 comments, Last at 08 Nov 2007, 10:54am by Pete


by Penrose 10,000 (not verified) :: Wed, 11/07/2007 - 2:43am

Is this recurring "link goes to this page" problem temporary? Is there some reliable behind-the-scenes fix?

by mm (not verified) :: Wed, 11/07/2007 - 2:48am

#1-the above is the article...they sometimes stick short articles like this over on the side.

by emcee fleshy (sd/atl) (not verified) :: Wed, 11/07/2007 - 3:00am

What reasonable person looks over the line at Brooks Bollinger and Adrian Peterson and thinks to himself: Nickel!

I swear, I think I saw five in the box at one point last week.

by emcee fleshy (sd/atl) (not verified) :: Wed, 11/07/2007 - 3:05am

3 - shut up, me, and read the AGS.

by navin (not verified) :: Wed, 11/07/2007 - 3:08am

Didn't San Diego destroy NE last year in Foxboro? And NE finished in the top ten.

by navin (not verified) :: Wed, 11/07/2007 - 3:11am

Ignore my stupidity, that was in 2005.

by lionsbob (not verified) :: Wed, 11/07/2007 - 3:48am

I think: 2004-easy schedule, breakout season
2005-hard schedule, down year
2006 easier schedule, good year
2007-harder schedule, tough go at it.

I don't think its all the coach there either. I think they are a really good team-just not good enough to win consistently

by Yaguar (not verified) :: Wed, 11/07/2007 - 3:50am

14-2 teams regress the following year, but the Chargers have regressed unusually badly.

I just can't see a Schottenheimer team allowing the single-game rushing record to be set against it.

by Speedegg (not verified) :: Wed, 11/07/2007 - 4:13am

Whoa! While not all blame should fall on Norv, a good deal of it should.

First, the defensive coordinator, Ted Cottrell likes to blitz his safeties and corners. That's okay, as long as the other defensive backs can hold up in coverage. They can't, but their secondary still blitzes.

On top of that, the secondary has problems passing off receivers. This was an issue last year, but seems to be worse this year. Continuity is good, but not of bad habits.

Norv's ability of developing young quarterbacks and wide receivers is lacking. Yes, Rivers showed his propensity for losing his cool and accuracy when blitzed, but he is horrible this year. He hasn't been able to carry the offense when the game is on the line.

Perhaps more telling, his receivers aren't helping him out. This is bad, when you consider one of his top receiver is the running back. The "real" receivers, Jackson, Floyd, and Davis haven't stepped up to make small plays or convert short yardage downs. If they can't even make the short yardage, they can't be expected make the long yards.

While it's expected for the team to regress from last year, it's the manner in which they lost. They haven't just lost, they're been humiliated and the coaching has a lot to do with it.

by FullMoonOverTulsa (not verified) :: Wed, 11/07/2007 - 4:34am

Is it at all possible that Wade Phillips is missed?

by John Morgan (not verified) :: Wed, 11/07/2007 - 5:24am

If your head coach is costing you at least one game and possibly two - that's a terrible head coach.

by TGT (not verified) :: Wed, 11/07/2007 - 11:11am

@11 Why are you assuming Norv's costing the team 1 game or two instead of Marty adding a game or two?

by The McNabb Bowl Game Anomaly (not verified) :: Wed, 11/07/2007 - 11:20am

Regression to the mean is not a causative force. It is descriptive, and it is predictive, but that's all.

Regression to the mean didn't cause the Chargers to be much worse this year. Regression, if it happened, means that the Chargers' success last year was flukish or unsustainable. Is that true?

DVOA, which takes regression to the mean into account, predicted that the Chargers offense would play at +18.4% and rank 4th. Last year their offense was +24.4% and 2nd, so that implies a moderate regression. As of week 9, their offense is +3.6% and ranked 15th.

I only mention offense because it is more sustainable than defense. Even if the Chargers regressed overall because they weren't really that good overall or on defense, it's a much shakier claim that they weren't really that good on offense. Regression to the mean does not explain how one of the most talented units in the league dropped from 2nd last year to 15th this year. The mean for one of the most talented units in the league is not average.

What I'm saying is that you can blame regression to the mean for the Chargers' win-loss record, and you can blame it for their defense, but you cannot blame regression to the mean for their offense. That I put on Norv.

by Brian (not verified) :: Wed, 11/07/2007 - 11:40am

13: You're right it is not a causative force. It didn't cause the Chargers to be worse. But the point of regression to the mean is that the Chargers really aren't that much "worse." They appeared better than they truly were last year, and they probably appear worse than they truly are this year.

by princeton73 (not verified) :: Wed, 11/07/2007 - 12:08pm

think: 2004-easy schedule, breakout season
2005-hard schedule, down year
2006 easier schedule, good year
2007-harder schedule, tough go at it.

they remind me of the late 80s Bengals under Wicky-Wacky

ping-ponging between SB appearances and not making the postseason, but I don't think there was much difference between the teams--just strength of schedule

by footballprofessor (not verified) :: Wed, 11/07/2007 - 12:33pm

FO may include regession to the mean in their formula, but it takes technical analysis to tell you when and how severe the regresson will be. Case in point, San Diego.


by Rich Conley (not verified) :: Wed, 11/07/2007 - 12:38pm

"14-2 teams regress the following year, but the Chargers have regressed unusually badly."

No Yaguar, they haven't. 14-2 teams, as the article says, average 9 wins the next year. The Chargers are 4-4. They've regressed pretty much exactly as 14-2 teams average.

by Otis Taylor 89 (not verified) :: Wed, 11/07/2007 - 12:38pm

What explains Seattle? They have the easiest schedule year after year of any top tier talent teams, have a possible HOF coach, have a big home field advantage loud stadium, but seem to be mediocre every year. They alway make the playoffs without problems every year because of their lite schedule.
Maybe their coach isn't all that great or is the talent weak?

by Rich Conley (not verified) :: Wed, 11/07/2007 - 12:48pm

"egression to the mean does not explain how one of the most talented units in the league dropped from 2nd last year to 15th this year. "

No, but playing almost all top half of the league defenses does. They've played an extremely tough defensive schedule this year. They've played NE, GB, Chicago before injuries, Minny, KC. Almost all of their games have been against good defenses. The games that haven't been, they've reeled off points.

DVOA's opponent adjustments aren't perfect. Teams tend to come out of runs against good teams with a low DVOA, and rise back up. SD is doing that. Buffalo is doing that. Cleveland is doing that. All got pounded early in the season by a great team or two, and are just now recovering DVOA-wise.

by RickD (not verified) :: Wed, 11/07/2007 - 1:09pm

re; 5
That game was in 2005. The Pats and Chargers didn't meet in the 2006 regular season.

by RickD (not verified) :: Wed, 11/07/2007 - 1:19pm

re: 17
Historically, the Seahawks are not a very strong team. Their Super Bowl year is the exception, not the rule. You'd be better off asking why they succeeded that year instead of why they are not succeeding every year.

Holmgren may be a touch overrated, but anybody who leads two completely different teams to the Super Bowl cannot be all bad.

by Joe T. (not verified) :: Wed, 11/07/2007 - 1:52pm

What about AJ Smith? Its his personnel moves that resulted in Norv, and the fact that they did not acquire any decent wide receivers.

by JThrash (not verified) :: Wed, 11/07/2007 - 1:52pm

thanks for this great, well-reasoned article. Everyone agrees hiring norv was a bad idea - but you're right to point out that a decline of some kind was very likely. One thing I would say is that unlike last year's other 13+ win teams, San Diego was built on offense, which I believe FO thinks is more reliable season-to-season. So they should have been less prone to decline, (and I don't think they've suffered any major injuries).

by The McNabb Bowl Game Anomaly (not verified) :: Wed, 11/07/2007 - 2:42pm

Re: 14

I agree with you as regards to defense and overall performance. But you can't tell me that the SD offense was a mirage. A bit over their heads, yes, but way over, no. Their offense was very good in previous years as well. And FO has demonstrated that good offense is sustainable over several years. So regression to the mean does not account for the severity of the offense's regression.

Re: 16

Your link seems to be about winning percentage. I'm not debating that. I agree that regression to the mean is probably the main explanation why SD is winning fewer games, meaning they shouldn't really have been so good last year. I'm talking about offense. If you can show that the offense was playing way over their heads, and talent-wise is really league average, fine. But I don't think that's the case. I think that a small step down was severely compounded by Norv's mismanagement (remember, the offense is his baby).

by Rich Conley (not verified) :: Wed, 11/07/2007 - 2:54pm

24.My argument is that because of the quality of defenses they've played, DVOA isn't accurately reflecting the strength of their offense.

DVOA by its nature assumes some bit of linearity. When a +30% offense plays a -10% defense on an even field, you expect the same results as when a +20% offense plays a 0% defense, but thats not always the case.

When they've played mediocre opponents, they've piled on points. Unfortunately, they've only played Houston, Oakland and Denver for mediocre opponents. Everyone else they've played has had a great defense.

San Diego is a run first team. They've played a LOT of teams with dominant run defenses.

by lionsbob (not verified) :: Wed, 11/07/2007 - 2:56pm


Well to be fair, he had Eric Parker who got hurt and many thought Vincent Jackson was going to break out this year. He drafted a WR in the 1st round and traded for Chambers-his main problem might be getting too many of the same WRs.

by countertorque (not verified) :: Wed, 11/07/2007 - 3:42pm

The next season, they averaged nine wins per team. Only three teams won more than 10 games (2003 Patriots, 2005 Steelers, and 2006 Colts).

I think you mean 2004 Patriots. The 2002 Pats won a couple less than 14.

by Independent George (not verified) :: Wed, 11/07/2007 - 3:51pm

Is it ALL Norv's fault? Obviously not. But it's also clearly not all, or even mostly, regression towards the mean or strength of schedule, either:

2007: 4.8 % OVR, 3.6% OFF, DEF: 5.1%, 0.3% SCHED, 4-4
2006: 29.9% OVR, 24.4% OFF, -1.1% DEF, -6.6% SCHED, 14-2
2005: 21.5% OVR, 18.1% OFF, -3.1% DEF, 10.6% SCHED, 9-7
2004: 19.9% OVR, 20.9% OFF, -3.9% DEF, 2.0% SCHED, 12-4

2006 was an aberration, but regression towards the mean impllies around a 20% offensive DVOA, and not 3.6%. And if anything, the defense should be better than 2006, not worse.

by PatsFan (not verified) :: Wed, 11/07/2007 - 3:52pm

Re: #24

He said 2003 Patriots, who like the 2004 team were 14-2 (the 2002 team was 9-7).

by mrparker (not verified) :: Wed, 11/07/2007 - 3:52pm

Honestly fellas,
The chargers have played some sick defenses,

Minnesota, Gb, NE, and KC who are all negative DVOA on defense. Any coincidence that these are there 4 losses?

The second half of the season brings another four of these defenses(Bal,Jax,Ind,Ten). If they are do anything they will have to win each of the other four games and at least 2 against these tough defenses. A team with this kind of offensive fire power is bound to find a way to win 25% of games against tough defenses.

by PatsFan (not verified) :: Wed, 11/07/2007 - 3:53pm


I see what you mean, #24. Yeah -- the XP should have said "2004 Patriots".

by Independent George (not verified) :: Wed, 11/07/2007 - 4:03pm

#27 - If you're looking only at W-L, you're right, but DVOA takes SOS into account, and by these measures, SD has suddenly gone from elite to mediocre. Given the competition, they could still win the division at 9-7 or better, but unless their performance undergoes a sudden rebound, it's hard not to conclude that they've seriously underachieved this season.

by Reinhard (not verified) :: Wed, 11/07/2007 - 4:20pm

This is just from personal observation, but... under Marty, the Chargers would run a lot, but it wasn't the same play over and over, in fact, it was a dizzying array of inside and outside runs that helped sustain the running game. Under Norv, I think some of this creativity is missing.

by Rich Conley (not verified) :: Wed, 11/07/2007 - 4:31pm

"If you’re looking only at W-L, you’re right, but DVOA takes SOS into account,"

DVOA TRIES to take SOS into account. It doesn't do it perfectly, because theres no way to absolutely predict what the difference in performance between a +x and a -x team will be.

Theres a reason Buffalo and San Diego have risen drastically the last couple of weeks: San Diego is not as bad as Green Bay and New England made them look, and Buffalo is not as bad as New England and Pittsburgh made them look.

DVOA is tweaked to be accurate for the league AS A WHOLE. That means that any teams on the fringes, IE, the outliers, are going to have some inherent inaccuracy. In the case of the Bills, they've been destroyed by two historically great teams. DVOA says they should get destroyed, but not as badly as they did because DVOA assumes that theres some linearity, IE a +20% team outperforms a 0% team by 10% more than a +10% team does, when thats not necessarily the case. A 10% dvoa difference may lead to a close win, a 20% may lead to a mismatch where one team hangs 60 points on the other.

If DVOA's opponent adjustments were perfect, team's DVOA's would essentially be straight line (except for performance declines related to injury). They're not.

I'm not saying that DVOA's opponent adjustments are too weak, or too strong, but that true opponent adjustments probably lie upon some sort of curve, where ratings are tempered along the outliers.

Indy should be expected to blow out San Francisco. IMO, whether their VOA for that game is +80%, +150%, or somewhere inbetween isn't really indicative of anything. Theres too huge of a talent discrepancy to think that its precise.

by Yaguar (not verified) :: Wed, 11/07/2007 - 4:53pm

33: They did indeed run the same play over and over against the Raiders last year. Marty deemed the Oakland offense so incompetent that he decided the best course of action was to run the HB off-tackle play the entire game and watch Oakland implode.

Technically, he ran two plays, his vanilla off-tackle run and his off-tackle run with the fake end around.

by sundown (not verified) :: Wed, 11/07/2007 - 4:59pm

#34: "If DVOA’s opponent adjustments were perfect, team’s DVOA’s would essentially be straight line (except for performance declines related to injury). They’re not."

There are many "performance declines" unrelated to injury and virtually none of them are predictable. Guys fall down at the wrong time and and give up TDs, some game plans are better than others, players have off days, certain rivals somehow manage to play each other tough regardless of record... No statistic will ever be able to accurately take the human equation into account--and that's why it's enjoyable to watch.

by Bobman (not verified) :: Wed, 11/07/2007 - 6:28pm

"Regression to the mean" question. I have always assumed this referred to a mean derived from a large pool of data points--in this case say 30 seasons for all NFL teams--a few hundred data points.

But in #28 above, Independent George brings up a good point, in that is it SD's mean or everyone's mean that matters here?

I brought up a similar issue in preseason when the FO ratings system projected Indy to have 9 wins IIRC. Regression to the mean on their 3rd down performance was one of the specific points. I called bullshit on this and pointed out that Indy's mean for 3rd down conversions was to be ranked in the top 3 for about 4 years. I saw no reason to expect a downturn because being the best WAS their mean. (and again they're #2 by a slim margin this year with an easier 2nd half sked coming up).

Another example--Say Purple Jesus averages 6 YPC this season, 6.5 next year, 7.1 the following year, and then a crazy 8.5 yards after that. Will he be expected to regress to the NFL's mean of 4.1, or his own mean of 6.6? (Sorry if that idle speculation made some Vikes fans wet their pants. If he does that, I just might adopt them as a 2nd team.) We'll have to consider this for Brady's 2008 stats was well--is he now on a Manning-like plateau where his next 5 years will redefine his statistical performances compared to the past 5? Or will he regress to the NFL mean with a QB rating of 85, 25 TDs and 18 INTs (or whatever)? Not likely.

So whose mean is more valid for most of these R-T-M discussions--a specific player's/team's, or the whole universe of data points?


by cjfarls (not verified) :: Wed, 11/07/2007 - 6:29pm

Theres too huge of a talent discrepancy to think that its precise.

I think the talent piece is why everyone is so surprised about SD... last year they were the consensus "most talented team", even if not the "best team". To crash the "most talented team" so horribly, I think you have to look at why. I can think of 3 reasons, all of which may apply to SD...

1) Did we overrate their talent last year, or have injuries lowered that talent base? Phillips and McNeil don't look so hot anymore... Parker hurt at WR... Wasn't their center hurt, which led to lots of "up the middle" pressure on the QB?

2) Are there holes in certain positions that drag the overall team down? WR is one place where you could make that argument... Secondary?

3) Is the scheme putting the talented players in bad positions (i.e., bad coaching)? Playing nickel D vs. Minnesota...

Basically, you could make a case that all 3 of these reasons are contributing to SD's decline.

Luckily for SD, injuries have trashed the Broncos, the Chiefs are mediocre, and the Raiders are the Raiders so I still put their chance at the playoffs as better than even. Yeah.

by footballprofessor (not verified) :: Wed, 11/07/2007 - 6:36pm

#37 - I think you've got to look at that individual team's mean, not the league's mean.

by Bobman (not verified) :: Wed, 11/07/2007 - 6:46pm

Nicely explained in #34. Save that graf and re-post from time to time; it's a clear way to get some of the subtleties across (and also helps defuse flame wars when one team is clearly an outlier and their fans are frustrated by how DVOA handles them).

by Rich Conley (not verified) :: Wed, 11/07/2007 - 7:05pm

This whole thing basically comes down to SD blowing that game to KC. Its an upset, it happened. If they win that game, they're 5-3, and they've lost to NE, GB, and Minny.

NE and GB are great teams. Minny is a good team thats a bad matchup. Is anyone harping on Norv if that happened? I don't really think Marty would have been any better than 5-3 at this point.

The biggest issue I've seen with SD is they've gone from having an elite LT to having one thats a liability. Anyone know what the hell happened to McNeil? Did a year of tape give coaches something to exploit with him? Is he not strong enough? Not quick enough?

by Richard (not verified) :: Wed, 11/07/2007 - 8:36pm

I think a lot of offenses would look considerably worse if they lost their best receiver for the season. Also, losing Hardwick really hurt against Minnesota.

by Richie (not verified) :: Thu, 11/08/2007 - 2:04am

How much credit does Cam Cameron get for San Diego's success last year?

I was just reading the Miami chapter of Prospectus and there was an essay in there about how unusual it is for an offensive coach to start new as head coach for a team with poor offensive DVOA and turn it around in one season. The Dolphins were at -11.8% offensive DVOA in 2006, but this year the Dolphins have increased by over 14% to +2.9%.

On the other hand, San Diego has fallen from 24.4% in 2006 to 3.6% this year.

Of course there are many other factors, but maybe despite Miami's craptastic season, Cameron is able to improve the offense a bit.

by Flux (not verified) :: Thu, 11/08/2007 - 7:29am

I assumed SD would have hard times for at least the first half of the season with new offense and defensive schemes to learn/adapt to. Rivers problems are a surprise, though.

Any studies or stats on the win/loss changes teams can expect after changing out their OC, DC, and HC in the same season? I'd assume that would be hard to compare, since such coaching clean sweeps usually come about by 3-13 style necessity, not 14-2 hubris, but there must have been some good teams that have changed horses midstream in this fashion in the past?

by Pete (not verified) :: Thu, 11/08/2007 - 10:54am

There are many reasons why San Diego is not doing as well and Strength Of Schedule is one. However, I believe Norv Turner is a significant downgrade in Head Coaching (especially outside of the playoffs).

A bigger issue for me was losing all of the other coaches. There is a reason that Indianapolis does so well on offense and part of it is continuity of its offensive coaching to go with its Head Coaching.

Changes in coaching is often a result of a team that is not performing well or a coach that is perceived to be doing very well. Are there any other instances of such widespread changes in coaching where a team did well? Actually, considering the number of changes I was surprised they have won as many as they have.

I should look at the individual rankings for San Diego, but I suspect Rivers is having a poor year (especially compared to Brees). Rivers also does not have the receivers he needs to do well and appears to be falling into bad habits when pressured.

However, I suspect San Diego has enough continuity of players to beat the bad teams , go to the playoffs and lose to Pittsburg, Indy, or New England.