It’s old news now, but I’ll post anyway. The last two years I tracked the efficiency of all NFL quarterbacks using my passing offense metric. See below for an explanation of the statistical details: It's the same text I've posted the last two years.
After a very average 2008 season, Romo bounced back to record the highest observed point per pass value of any starting quarterback in Cowboys history. However, it was not the greatest season by a starting quarterback in Cowboys history, because other Cowboys quarterbacks have turned in better seasons relative to the rest of the league. In particular, Roger Staubach played almost all of his career in a league where passing was obscenely difficult, whereas Romo is playing in an era when passing efficiency is at an all-time high. Still, what Romo accomplished was impressive. His 2009 season was easily the best of his career, far surpassing his 2006 season and reversing two straight years of decline.
Background on my Point Per Pass Metric:
I've been using a passing offense metric for many years now to gauge how well a QB is doing. Inspired by baseball SABRmetrician Bill James, I performed linear regressions of NFL statistics and concluded from a big picture point of view, only two statistics mattered: Yards gained from scrimmage, and turnovers. The best fit to matching points scored came when assuming the following coefficients:
Ten yards gained from scrimmage = +1.0 points; and
One turnover lost = -6.0 points.
Simply put, teams that score points rack up yardage and don't commit turnovers. Note how powerful turnovers are: A team can, for example, gain 55 yards of offense, but if they turn it over the next play, they actually ended up hurting their team.
With that in mind, I created the points per pass metric, which calculates the effectiveness of quarterbacks. I consider it a better measure of quarterback performance than the official NFL rankings, since it weighs the value of fumbles, and has direct ties to points scored. The above two coefficients are used to determine, on average, how many points a quarterback (and his offensive teammates, since everyone else contributes to his success or failure) creates with each passing attempt. It takes the simple yards per attempt metric we're all familiar with, adjusts it for sacks, and further adjusts it for turnovers. One interception equates to minus six points; one fumble equates to minus three points. I treat fumbles as half a turnover, since there's essentially a 50/50 chance of recovering or losing a fumble. The results will probably be unsurprising for the most part, but sometimes they can appear odd. One of the things that may cause these oddities are fumbles. Most people, when looking over a QB's stat line, don't think about fumbles; they just look at yardage, attempts, touchdowns, interceptions, and maybe sacks. But fumbles are very important, since they are essentially half a turnover.
This season I have included not only the raw points per pass value, as I have in seasons past, but also the normalized value, by dividing the raw result by the league average. Therefore, an average quarterback will have a normalized value of 1.00, and an above average quarterback will have a value greater than 1.00. A rigorous statistician would have done research to make sure the mean or average is an appropriate normalizing factor—as opposed to the median, quartile or something else—but time has been at a premium for me this year, so the mean will have to do for now.
Revisiting a Prediction of Romo’s Career Trajectory:
At the end of last season, I compared Romo to the most-similar group of NFL quarterbacks and noted this group underwent a long-term process of performance decline from their mid- to late-twenties until their early thirties. In particular, every one of the comparison QBs declined at the age of 29. This group was unusual, as most quarterbacks improve until their late twenties, then decline thereafter. However, Romo broke the mold with his sterling 2009 season. I did recognize back then that the most-similar group to Romo did experience one-year reversals of their several year decline, so he may not be out of the woods yet, although his normalized score of 1.54 was the highest of any of the comparison group. Was this just a one-year fluke, or has Romo turned a corner in his career? I’d like to think the latter, but the ghost of 2008 could always come back to haunt us. Let’s hope.
In any event, Romo’s interception percentage has improved with each year in the league. From a high of 3.9% in 2006, he dropped slightly to 3.7% in 2007, to 3.1% in 2008, to a magnificent 1.5% last season. This is obviously cause for encouragement, as turnovers are the most important statistic in football.
Notes on the rest of the league:
- The league average last season dipped slightly to 0.397, a modest reversal from 2008, which was the highest value since the 1970 merger. The long-term trend is clear, however: Passing efficiency has been improving over the last four decades, and I see no reason for that trend to reverse.
- None of the rookie quarterbacks turned in a season worthy of note, after Ryan and Flacco, turned in outstanding rookie seasons last year. Flacco improved on his 2008 season, while Ryan turned in a decent but not exceptional performance.
- The Brett Favre rollercoaster continues. Washed up in 2005, rejuvenated in 2007, an embarrassment in 2008, only to turn in by my measures his best season ever in 2009. Given how erratic his seasons have become, anyone want to bet he’ll have another good year at the age of 41?
- As I predicted last year, the best quarterback in the NFL is now Phillip Rivers, a crown I expect him to wear for the next few years.
- Peyton Manning was fortunate to win his fourth MVP award. I don’t begrudge him for it, as I think he will be remembered as the greatest quarterback in league history, but clearly he and Brady are in decline and Rivers is now reaching his peak.
- The Eagles were probably right to let Donvan McNabb go. At 33, he is declining and his health is a growing concern, although he is the greatest quarterback in Eagles history. His 2009 season was another very good one, and his career resume is almost worthy of a Canton induction. While I think Kolb will be a good quarterback, and next season he will probably be better than McNabb would have been had he stayed, I don’t know that Kolb will be in the same league as McNabb in his prime. This will be an interesting season to watch for both the Redskins and Eagles.
- For those who recall my discussions from the two last years, I noticed Drew Brees alternated excellent seasons with not-so-good years, and expected 2009 to be one of his off seasons. However, he went against form and turned in his second best season since his incredible 2006 season. Given his age and his strange cyclical career pattern, I expect him and the Saints to decline next season.
- Many BTB posters doubted Aaron Rogers would be a good quarterback, but he’s turning into one of the best quarterbacks in the league. Might we see a return to the days of the 1960’s, when the Cowboys and Packers slugged it out for league supremacy? We can only hope…
The 2009 Rankings:
As I did at the end of last season, I ranked the quarterbacks by efficiency in three groups, based on the number of passing attempts:
- Those with at least 160 attempts;
- Those with less than 160, but at least 30 attempts; and
- Those with less than 30 attempts.
Regular Starting Quarterbacks:
Quarterbacks with between 159 and 30 attempts:
Quarterbacks with less than 30 attempts:
|St. Pierre, Ari||-1.95||-4.91|