C Scores for Current Quarterbacks

I thought it might be illustrative to show you C scores for all the quarterbacks who qualified in 2009.  With Kurt Warner retiring at the end of last season, it is certain that not all of them will qualify again in 2010, and, almost assuredly some of the remaining won't qualify in 2010.  The difficulty in looking at these players is their body of work.  Not all of them will have a C7 score, our standard measure.  That being said however, it is still worth a look.  Instead of simply limiting the list to those that have a C7 score, we will look at all of their C scores (C1, C4, C7 and C10).

Here's what the list looks like:

Not too many surprises here.

Did you expect someone other than Peyton Manning to be the best passer in the game today?  If you did, I'd love to hear from you, and I'd like to see the analysis.  Peyton Manning is one of the all-time best (see here and here), and most certainly the greatest passer of his era.  Based on C7, I currently have him 7th all-time (C7 of 644), right behind both Fran Tarkenton and Len Dawson who are tied for sixth at 646.  He has an outside chance (I'd say about 25%) of catching Sammy Baugh, who is 5th with a C7 of 654.

In the article I wrote on Kurt Warner (see here), I showed that Warner compares favorably to players like Drew Brees, and Tom Brady.  In my recent post formally introducing C scores I suggested that as far as the Hall of Fame, that Warner appears to be right on the fence.  I certainly would make the argument that Ken Anderson should be in before Warner.

In that same article I also discussed Tom Brady and Drew Brees.  I think if they both played long enough that they would both be in the HOF, and I'm fairly certain that Brees would end up as the better passer.

As far as the next group of players, certainly Carson Palmer and Philip Rivers appear to be on their way to becoming good passers, although they've still got a few years ahead of them before we can make any definitive statements.

And finally, looking further out in to the future, I'd say that Matt Schaub is an up-and-comer, and, really taking a flyer, perhaps Aaron Rodgers can parlay his early success to be considered a great passer.  Only time will tell.

C Scores - A New Way to Evaluate Pro Football's Best Passers of All-Time

It has taken me two years, many, many iterations, and countless hours of mental anguish, but I think I've finally settled on a reliable method by which I can evaluate any quarterback's passing ability versus any other quarterback's passing ability regardless of when they played, or for how long they played.  So, for example, I can compare Peyton Manning versus Sammy Baugh, or, Otto Graham versus Brett Favre, or, Sonny Jurgensen versus Dan Marino.  You get the point.  It all started coming together for me as I wrote my post on Manning versus Brees versus Favre.  While I had already figured out how to effectively compare one quarterback's given season to that of another's given season, I had as yet to figure out an effective method by which we evaluated careers.

The inspiration came to me as I read Michael J. Schell's book, Baseball's All-Time Best Hitters, where he went about solving a different problem altogether, but had essentially the same characteristics of the problem I was trying to solve.  He was trying to account for the fact that for many hitters with long careers, their batting averages declined after they reached their mid-thirties.  And, he didn't think it was fair to compare a hitter who had played into their late thirties or early forties to a player that had not.  He chose to account for this by using a "late career adjustment".  What he did was to look only at a player's first 8,000 at-bats.  


I adopted this notion, and, instead of using a player's first x years, came up with the idea of using his best x years, given that a player's passing ability, as measured by CMTI, and compared to that of his peers tends to be a little volatile from year to year.


Deciding what x was going to be was an issue.  I wanted to balance outstanding achievement with duration.  In other words, I wanted to see who had performed at an exceedingly high level for a long time.  Remember, from my previous post, the average number of years a quarterback qualifies is 4.125.  The median is 3.  


I thought that a good starting point was to use 4 years.  This measure would include 169 players, or a little more than 40% of my database of 416 players going back to when the NFL officially started keeping statistics, and including both the AAFC in the 1940's and the AFL in the 1960's.


If I used 7 years, then I'd get 95 players, or almost 25% of the total.  That seemed reasonable for a couple of reasons.  First, 25% seemed like a good cut-off, albeit arbitrary.  Second, it would allow me to discard the worst years for those quarterbacks who had 8 or more years, which seemed like an appropriate way to reward longevity.  


I could have looked at 10 years - in which case, we would be limiting ourselves to 50 quarterbacks, or about 12% of the database, a rather small group, and, as we shall see, excluding many superb passers who didn't quite make it to 10 years.  Keep in mind that the median number of years a player qualifies, is 3 years.


My basic method for evaluating a player's performance in a given year is to look at his CMTI, and then, based on the mean and standard deviation for that given year, relate his performance to that of his peers.  Since the aggregate accumulation of these measures over the past 78 years looks very much like a normal (bell-shaped) curve, we can use the bell-curve to convert these measures to percentile ranks, giving a numerical value ranging from 1 to 99 for each of these performances.  The sum of a given quarterback's 4 best such performances are then used as my C4 calculation, and the sum of his 7 best performances are my C7 calculation.  Obviously, then the maximum possible value for C4 is 99 * 4 = 396, and, commensurately, the maximum C7 value is 99 * 7 = 693.  As I mentioned earlier, I've also calculated a C10 value for those players with an exceptionally long career.  Obviously, if we did this for every year a player qualified, one could create a career C score for each player.


Let's take a look at the lists.  We will start with C4.

Wow!  What a list.  Not bad for starters.  Remember, this is a ranking based on a quarterback's 4 best years as a passer.  Look at the top 14 on this list.  12 of them are in the Pro Football Hall of Fame!  Peyton Manning surely will be when he is done.  That's 13 out of 14!  Ken Anderson ranks 3rd all-time as a passer according to this list.  It is important to keep in mind that this is a list of the top-ranked passers, not top-ranked quarterbacks.  It is hard enought to determine a ranking of passers, so it would stand to reason then that it is much harder to determine what makes a top-ranked quarterback.  I don't know how the NFL goes about determining who gets in to the Hall of Fame and who deos not, but it sure seems odd that Ken Anderson is the only player in the top 14 on this list that isn't (assuming that Peyton is in, of course). 

One of the most aesthetically pleasing aspects of this list, especially looking at the top 15, is that every era and every decade is represented.  There does not seem to be a bias.  I would think that is an admirable quality of any top-ranked list in that it shows that the measure used to determine who is better, isn't necessarily biased towards a particular era - as opposed to say, the list of top ranked passers (see here and here) in terms of the NFL Passer Rating system at the Pro-Football Hall of Fame.  


Look at Steve Young's C4.  That's almost unbelievable!  The highest C4 possible is 396.  In other words, that is being in the 99th percentile four years.  Well, Young comes close.  His 1996 and 1997 seasons were in the 99th percentile, and his 1992 and 1994 seasons were in the 98th percentile.


In my previous post, we discussed Kurt Warner's merits as a passer.  We ignored any discussion about whether he will be enshrined in Canton.  Based on this list, it would appear that he is right on the fence.


There are a total of 27 quarterbacks on this list that are members of the Hall of Fame.  There are a total of 31 quarterbacks that have been inducted into the Hall of Fame.  The four that are in the Hall of Fame, but are not on this list are omitted for good reason.  They all played in the 'early years' of the NFL - prior to the keeping of official statistics.  They are, Jimmy Conzelman, who played from 1921-1929, John (Paddy) Driscoll, who played from 1920-1929, Earl (Dutch) Clark, who played from 1931-1938 and actually had two very good years in 1934 and 1936, and Benny Friedman, who played from 1927-1934, and who, many during his time argued was the finest passer of his time.  It is most unfortunate that we don't have official statistics that would show that.


OK, what about C7?

Woah!  An even better list than C4!  First, while the ordering changed, the top 15 stayed exactly the same as the C4 list, which probably suggests more of the power of the C4 list than anything else (in other words, a quarterback's best 4 years is a pretty good indicator of their passing ability).  However, now, we not only have 13 of the top 15 in the HOF (I am considering it a foregone conclusion that Peyton Manning will be inducted into the HOF), but 16 of the top 20 are either in the Hall of Fame or will be (I am also considering it a foregone conclusion that Brett Favre will also be inducted into the HOF).  That is a phenomenal list.  


It seems obvious then, that, in order to be inducted into the Hall of Fame as a quarterback, one must also have been a great passer.  Having said that, it's even more shocking to me now the omission of Ken Anderson from the HOF.  I simply do not understand why he is not in.  I will have to post an article on Ken Anderson in the near future.


What does C7 say about Kurt Warner?  Again, right on the fence.  

From my vantage point, it certainly appears that we should be discussing putting Ken Anderson in the Hall of Fame ahead of Kurt Warner.


Finally, we'll take a look at C10.  This list only includes 50 quarterbacks, and many exceptional passers are not on this list, simply because they didn't qualify in at least 10 years.

The story is similar to what we've already seen with the C4 and C7 lists.  14 of the top 15 (if you include Peyton Manning and Brett Favre as in the Hall of Fame) are or will be in the Hall of Fame.  The lone exception is - you guessed it - Ken Anderson.


There's several conclusions that I can draw from all of this.


I feel pretty good that I've come up with a method by which I can determine the all-time best passers in the history of professional football.  I also feel that this method will stand the test of time.  It will work regardless of how the game changes over time.  It is a method that allows me to conveniently compare players who played in different eras, and it allows me to compare players who have had different career lengths.  


Although being inducted into the Hall of Fame as a quarterback shouldn't be a criterion by which we evaluate a quarterback's passing ability, it does provide a reasonableness check of the method I've employed.  Given the likelihood of being in the Hall of Fame and showing up at the top of these lists, one could theoretically use it as a measure of whether a quarterback will be inducted into the Hall of Fame.  Obviously, there are other factors that enter that equation, but, I can draw some conclusions as to what might be necessary as a passer to be considered a good candidate for the Hall.


A C4 score of 370 or better is a must to be a shoo-in for the Hall.  The caveat there being the quarterback would have to had at least 8 seasons where they qualified.  Looking at C7, I'd say  a C7 score of 625 or better is a requirement, although a score of 600 or better conceivably also works.  A C10 score of 775 or better would be considered a must to have any chance of being inducted into the Hall of Fame (in my opinion anyway).


As I mentioned earlier in the article, I think C4 doesn't consider enough years.  Conversely, I think C10 is too exclusive.  C7 is a good compromise.  I could have created a C8 or C6, but C7 feels like it strikes the right balance between excellence and longevity.  From now on, I will use C7 as the standard measure of a player's career passing prowess, although I may use C4 and C10 where appropriate.  For example, if a player does not have a C7 score, I may use C4 as an early gauge, or, I may use C10 to compare to passers who have had lengthy careers.


Well, now that we've developed the method by which we can fairly present any quarterback's career as a passer, the natural question is, who is the greatest passer of all-time?  My method (C7) would suggest it is Joe Montana.  Steve Young would come in a close second.  You could also look at C4, and you'd see that they are the top 2, although in reverse order.  How good Joe Montana was, and for how long he performed at an incredibly high level, is evident by looking at C10 scores.  He is the only passer in the history of professional football to have a C10 score exceeding 900, and, at 939, he is 50 ahead of Peyton Manning.


A quick digression here, in case it wasn't obvious.  C scores can never decrease, only increase.  So for example, Peyton Manning's scores can only increase from here on out.  Since we consider a player's best years, if a subsequent year for a player isn't one of the best that already was included in the score, then it wouldn't count towards that score.  It would only count if it exceeded, and thereby replaced, one of the years already included.  Since Peyton's 10th best season so far is a 79 (his performance in 2007 was in the 79th percentile), he would have to have a performance better than that in the future to increase his C10 score (I would consider that quite likely).  On the other hand, his 7th best season is an 85 (his 2009 season), and I'd say that he's only about 50/50 to improve upon that, and thereby increase his C7 score (and if he did improve upon that, he would also improve his C10 score).


So, of the current crop of players, who might eventually knock on the door of the Hall of Fame?  Drew Brees and Tom Brady are currently ranked 21 and 22 on the C7 list with scores of 570 and 567, respectively.  A few more good years, and they would move up the ladder.  For example, in the case of Drew Brees, his score of 570 is made up of scores of 93, 93, 89, 88, 77, 75 and 55.  It's almost a guarantee that he would end up dropping the 55.  I think it's a foregone conclusion that his C7 score will eventually exceed 600 by a comfortable margin.  What about Brady?  Well, he is probably already a shoo-in for the Hall on account of his three Super Bowl victories.  But, as a passer, he appears a lot weaker than Brees.  Brady's C7 score of 567 is made up of scores of 98, 89, 80, 76, 75, 75, and 74.  Given his history, I don't see him improving too much from the 567.  Perhaps when it is all said and done, he might end up in the 580-590 range.  One never knows though.


What about the next generation of passers?  Who might be good candidates to have great careers as passers?  Chad Pennington, whose current C4 score is 366, one less than that of Kurt Warner, is an interesting case.  However, given his history of injuries, he may not be able to accumulate a solid C7 score.  If he has one decent year, say, in the 70th percentile, then his C7 score would be 575.  There are two players that I think could potentially have great careers based on their current C4 scores - Carson Palmer and Philip Rivers.  Based on their yearly scores, I think Philip Rivers might be the better bet, even though Palmer currently has the higher C4 score.  Interestingly, Philip Rivers currently ranks 2nd to Steve Young on the all-time passer rating list.  Of those who don't even have a C4 score, Matt Schaub has shown excellent early potential.

Quarterbacks and the NFL Draft - Part 4

In my last post, we looked at quarterbacks and their expected performance as compared to where they were drafted. We concluded that their on-field performance cannot be attributed to their draft position, and perhaps those drafted earlier play a bit longer. There definitely was a correlation between draft order, and their likelihood of actually playing in the NFL (playing as defined by throwing enough passes in a given year to qualify statistically).

All we really looked at in the previous post were averages over the past 30 years. We didn't spend any time looking at individual quarterbacks. In this post, we'll do so. We'll take a stab at answering the following question: Which quarterbacks have been the surprises, or the diamonds in the rough? These would be the quarterbacks that, when drafted, either had little likelihood of actually playing in the NFL, or, even when thought that they would play, surprised us as to how well they played and/or how long they played. These would also be quarterbacks that were drafted early in the draft (perhaps even in the first round), but worked out much better than the earlier picks.

Here is my list of the 10 best surprises of the NFL Draft over the past 30 years. Admittedly, it is somewhat subjective, but I do use objective criteria to determine the list.

10. Matt Hasselbeck (1998, 6th Round, 187th Overall Pick, 6th Quarterback Drafted) - Hasselbeck was drafted by the Green Bay Packers out of Boston College behind Peyton Manning (1), Ryan Leaf (2), Charlie Batch (60), Jonathan Quinn (86), and Brian Griese (91). Hasselbeck was traded by the Packers to the Seattle Seahawks in 2001. He has thrown enough passes to have qualified in 7 seasons, and his CMI has averaged 0.14 standard deviations above the mean over that period. His best year was in 2005, where he completed 65.5% of his passes and only had 2.0% of his pass attempts intercepted, a performance good enough to be 1.50 standard deviations above the mean.

9. Brian Griese (1998, 3rd Round, 91st Overall Pick, 5th Quarterback Drafted) - Griese was drafted by the Denver Broncos out of Michigan behind Peyton Manning (1), Ryan Leaf (2), Charlie Batch (60), and Jonathan Quinn (86). Griese became the starter in 1999 following the retirement of John Elway, and in 6 qualified seasons his CMI has averaged 0.42 standard deviations above the mean. His best season was 2000, where he completed 64.3% of his passes and only had 1.2% of his passes intercepted, worthy of being 2.04 standard deviations above the mean.

8. Neil O'Donnell (1990, 3rd Round, 70th Overall Pick, 5th Quarterback Drafted) - O'Donnell was drafted by the Pittsburgh Steelers out of the University of Maryland behind Jeff George (1), Andre Ware (7), Tom Hodson (59), and Peter Tom Willis (63). He started in 1991, qualified in 5 seasons for the Steelers, and threw enough passes in 2 more seasons - one for the Jets in 1997 and one for Cincinnati in 1998. He averaged 0.47 standard deviations better than the mean over those 7 years, and his best year was 1998, when he completed 61.8% of his passes, and was intercepted 1.2% of the time, good enough to finish 1.52 standard deviations above the mean.

7. Trent Green (1993, 8th Round, 222nd Overall Pick, 8th Quarterback Drafted) - Green was drafted by the San Diego Chargers out of Indiana University behind Drew Bledsoe (1), Rick Mirer (2), Billy Joe Hobert (58), Mark Brunell (118), Gino Torretta (192), Alex Van Pelt (216), and Elvis Grbac (219). He was the last quarterback drafted in 1993. He first threw enough passes to qualify in 1998 for the Washington Redskins. He qualified in 6 seasons altogether, the last 5 with the Kansas City Chiefs from 2001-2005. Over those 6 seasons, his CMI averaged 0.26 standard deviations above the mean. His best year came in 2003, when he completed 63.1% of his passes, and had 2.3% intercepted, good enough to finish 1.18 standard deviations better than the mean.

6. Mark Brunell (1993, 5th Round, 118th Overall Pick, 4th Quarterback Drafted) - Brunell was drafted by the Green Bay Packers out of the University of Washington behind Drew Bledsoe (1), Rick Mirer (2), and Billy Joe Hobert (58). He was traded to the Jacksonville Jaguars in 1995. He qualified in 8 straight seasons there, and then 2 more in 2005 and 2006 for the Redskins. Over those 10 seasons, his CMI averaged 0.64 standard deviations above the mean. His best year was 1997, where he completed 60.7% of his passes, and had 1.6% of his passes intercepted - good enough to be 1.23 standard deviations better than the mean.

5. Rich Gannon (1987, 4th Round, 98th Overall Pick, 7th Quarterback Drafted) - Gannon was drafted by the New England Patriots from the University of Delaware behind Vinny Testaverde (1), Kelly Stouffer (6), Chris Miller (13), Jim Harbaugh (26), Cody Carlson (64), and Mark Vlasic (88). He was traded to the Minnesota Vikings and qualified in three years (1990-1992) while there. He threw enough passes to qualify again in 1998 with Kansas City, and then from 1999-2002 with the Oakland Raiders. Over the 10 qualifying seasons, he averaged 0.64 standard deviations better than the mean. His best year was in 2001, when he completed 65.8% of his passes, and only had 1.6% of his attempts intercepted. This was good enough to be 2.54 standard deviations better than the mean that year.

4. Dan Marino (1983, 1st Round, 27th Overall Pick, 6th Quarterback Drafted) - This was the "Year of the Quarterback". Marino was drafted by the Miami Dolphins out of the University of Pittsburgh behind John Elway (1), Todd Blackledge (7), Jim Kelly (14), Tony Eason (15), and Ken O'Brien (24). He started immediately, and went on to throw enough passes in 16 different seasons, averaging 0.51 standard deviations above the mean CMI. His best year was 1984, where he completed 64.2% of his passes, and had 3.0% of his passes intercepted. This was good to finish 1.28 standard deviations above the mean CMI that year. Dan Marino was elected to the Pro Football Hall of Fame in 1995.

3. Brad Johnson (1992, 9th Round, 227th Overall Pick, 13th Quarterback Drafted) - Johnson was drafted by the Minnesota Vikings out of Florida State behind David Klingler (6), Tommy Maddox (25), Matt Blundin (40), Tony Sacca (46), Craig Erickson (86), Casey Weldon (102), Will Furer (107), Chris Hakel (112), Jeff Blake (166), Kent Graham (211), Bucky Richardson (220), and Mike Pawlawski (222). He qualified in 9 different seasons - first with Minnesota (1996-1997), then the Redskins (1999-2000), then Tampa Bay (2001-2003), and finally with the Vikings again (2005-2006). Over those 9 seasons, his CMI averaged 0.73 standard deviations better than the mean. 2005 was his best year, where he completed 62.6% of his passes and only 1.4% of his attempts were intercepted, a performance good enough to be 1.32 standard deviations better than the mean CMI that year.

2. Tom Brady (2000, 6th Round, 199th Overall Pick, 7th Quarterback Drafted) - Brady was selected by the New England Patriots from the University of Michigan behind Chad Pennington (18), Giovanni Carmazzi (65), Chris Redman (75), Tee Martin (163), Marc Bulger (168), and Spergon Wynn (183). After replacing an injured Drew Bledsoe in the second game of the 2001 season, he started every game until he got injured during the first game of the 2008 season. Over the 7 year period from 2001-2007, his CMI was good enough to average 0.82 standard deviations above the mean. His best year came in 2007, when he completed 68.9% of his passes, and was intercepted 1.4% of the time, good enough for 2.14 standard deviations above the mean.  Tom Brady will likely get into the Hall of Fame.

1. Joe Montana (1979, 3rd Round, 82nd Overall Pick, 4th Quarterback Drafted) - Montana was drafted by the San Francisco Forty Niners from the University of Notre Dame behind Jack Thompson (3), Phil Simms (7), and Steve Fuller (23). Although he played every single game in the 1979 season, he only threw 23 passes that year. Beginning in 1980, he qualified every year until 1990, when injuries slowed him down. He was eventually traded to the Kansas City Chiefs, where he played for 2 more seasons. Over those 13 years, his performances on the field, he averaged 1.54 standard deviations above the mean, including the remarkable feat of never having a season below the mean. His best season was 1989, when he completed 70.2% of his passes and had 2.1% of his pass attempts intercepted, a performance so good relative to his peers, that it ranked 2.96 standard deviations above the mean.  Montana was elected to the Pro Football Hall of Fame in 2000.

Now that's a pretty good list!

Brett Favre - Best Ever?

Brett Favre retired earlier this week.

He played in the NFL for 18 years. He set numerous NFL records during the course of his career. The most impressive has to be the fact that, as a quarterback, he started a record 269 consecutive regular season games. Peyton Manning is second on the list, his streak currently standing at 176 games. Third on the list is Ron Jaworski, his streak having ended at 116 games. Tom Brady is next on the list, but his streak ended in the first game of last season at 110 games. Peyton Manning needs another 94 games - he would have to start every single game through the 14th game of the 2014 season to break Favre's record. In addition to the four mentioned above, only two other quarterbacks in history - Joe Ferguson (107 games), and Dan Marino (95 games) have started that many games consecutively. I suspect Favre's record will never be broken.



People are fascinated with Favre. Many consider him to be among the all-time greatest to ever play the game. Some consider him the greatest ever. I do not belong to either group.


The media loved Favre. And vice versa. He never met a camera he didn't like, always seeking an opportunity to get into the limelight (of course, the media loved that). He also seemed intensely competitive, and the combination is what I believe led him to his unfortunate decision to come back for one more season in 2008.


Let's start from the beginning.


In 1991, the Atlanta Falcons took Favre in the second round of the draft. With Chris Miller as their starting QB, in 1992, the Falcons traded Favre to Green Bay. Favre started the season as the back-up to the 'Magic Man', Don Majkowski. In the third game of the season, against the Cincinnati Bengals, he replaced the injured Majkowski in the first quarter. With 13 seconds left, he threw a 35-yard touchdown that helped the Packers come-from-behind to win 24-23. He started the next game against the Steelers, a game the Packers won. The rest, as they say, is history, as he started every game for the Packers until his trade to the Jets following the 2007 season (for a detailed history of, or, more aptly, a tribute to Favre, see here).


The table below shows how Favre did each year.



Before we go on, some explanations.


In order to be able to truly compare Brett Favre to other quarterbacks so that we can properly gauge his place in history, we can't simply look at the NFL's passer rating system. First, we know that the average NFL passer rating in the NFL has been increasing over time. So, by simply using the NFL's passer rating system, the more recent quarterbacks would appear to have done better than quarterbacks from earlier years (see here and here for evidence). Second, we have to agree that the NFL's passer rating system is an accurate, if not adequate measure of a quarterback's performance. I have previously introduced a metric, CMI, which I believe is a better, if not more understandable measure of performance. CMI, however, also has the same bias as the passer rating system. One way to adjust for, and remove the bias favoring more recent quarterbacks is to look at each year's performance for each quarterback, and relate that to the average performance that year. The measure that we use is the standard deviation. I have discussed previously how using this measure tends to "normalize" performances across years. In other words, when a given year's performance by a particular quarterback is "normalized" to the average for that year, and we do that for every year, we can very easily see how that particular performance compares to other performances across years. Since CMI is very similar to the passer rating system, when using standard deviations, it shouldn't really matter whether we use CMI or the NFL passer rating system (there will be differences, and, I often include both so that you can see the differences). The two graphs below show how using either the "normalized" NFL's passer rating system or "normalized" CMI as measures compare to a standard normal curve with 1,451 observations (that's how many qualified quarterback seasons there have been over the past 69 years).



Ok, so back to the table.


Favre had a "pretty good", or, "above average" first year in 1992. Using the NFL passer rating, he finished 0.57 standard deviations above the average that year. Using a standard normal curve, that would mean between the 71st and 72nd percentiles. If we used CMI as the standard, then his performance that year, 1.24 standard deviations above the mean, would place him between the 89th and 90th percentiles.


He followed that with a sub-par year in 1993, finishing between the 30th and 31st percentiles according to the NFL passer rating system, or between the 35th and 36th percentiles using CMI. Then followed several "above average" to "very good" years (1994-1998), depending on your perspective, followed by a couple of mediocre years (1999-2000), followed by four above average years (2001-2004), followed by his two worst years (2005-2006). He finished his Green Bay tenure with an "above average" year in 2007.


He should have taken the opportunity to retire then.


His last year, his first full season not with Green Bay, was "below average". So he finished his career with 3 "below average" years out of 4. Perhaps the Packers brain trust was on to something when they decided that Aaron Rodgers was their future at the end of the 2007 season.


The two graphical illustrations below show each of Favre's seasons in terms of standard deviations from the mean. In case you haven't noticed, as much as I love statistics, I find that graphs are better way to illustrate a point than a table of statistical measures. I show the CMI graph first and the graph based on NFL passer rating next, for reasons that will become plainly apparent when you read on.





Ok, so until now, we've been looking at Brett Favre's career in a bit of a vacuum. Yes, we have compared his performances to an average, and yes, we have tried to put it into historical perspective, but I haven't given you any 'perspective'.


First, let's compare Brett Favre's career to some individual careers. The biggest problem we face in comparing Favre's career to any other individual career, is obviously the length of his career. There have been only 5 individuals who have thrown enough passes to qualify in at least 15 different seasons. Those are Fran Tarkenton (18 years), Brett Favre (17 years), Dan Marino (16 years), John Elway (16 years), and Johnny Unitas (15 years). So how does Favre's "picture" compare to these quarterbacks, all of whom are in the Hall of Fame?


Fran Tarkenton - a picture of "excellence". With a couple of exceptions, Tarkenton exceeded his peers consistently for a very long time. Quite remarkable. Without question, Favre's picture does not resemble that of Tarkenton.


Dan Marino - Marino was "above average" for many of his years, tailing off towards the end of his career. He was "very good" very early in his career. He really didn't have a "bad" year until his last, and wisely decided to hang it up after that. Although closer in resemblance, Marino's picture still looks better Favre's overall.


John Elway - Elway underperformed his peers much of his early career, exceeding the average in only two of his first ten years. He then was "above average", or even "very good" his last six years. He went out on top, having retired following the Broncos having won back-to-back Super Bowls (Super Bowl XXXII and Super Bowl XXXIII). I think it's safe to suggest that Favre's picture looks better than Elway's.


Johnny Unitas - In my opinion, Favre's picture most closely resembles that of Johnny Unitas. They both started out well, had a couple of mediocre years, then had several years where they outperformed their peers, and ended their careers with a few sub-par years.



What if we compared Favre's average performance (in other words, average each of his year's performance in terms of standard deviations), to other players? Well, over his career, in terms of NFL passer rating, Favre averaged 0.42 standard deviations above the mean (0.26 when looking at CMI). Tarkenton averaged 0.65, Marino averaged 0.63, Elway averaged 0.06, and Unitas averaged 0.51 standard deviations above the mean.


Let's expand the comparison list to players who qualified in at least 10 different seasons. 41 different quarterbacks make that list. The two graphs below illustrate where Favre ranks on those lists.



The same graph as above, except looking at it Using CMI as the measure of performance.




Looking at his career statistically, it is hard to make the argument that he belongs in the truly elite group of all-time quarterbacks - those that would be ranked in the top 3 or top 5 all time. I think it is fair to suggest that Favre has had a very good career. It was certainly a lengthy one, and, in that regard, it was exceptional. But as far as his actual performance on the field, there isn't a measure, or set of measures, that suggest that it was exceptional.


People will suggest that he holds the all-time record for yards, or touchdowns, for example. But that is merely a function of his longevity, just as much as he holds the record for interceptions thrown, all-time.


I also don't discuss measures frequently used as evidence of greatness. MVP awards, for example - these are popularity contests more than a reflection of outstanding statistics or an individual's value to a team (the NFL MVP award is given by the Associated Press). Pro-bowl selections for example are another popularity contest - just look at who got selected this past year in the AFC. Another measure frequently used is Super Bowls. Dan Marino didn't win any Super Bowls. Trent Dilfer won a Super Bowl. Winning percentage is also frequently used - last time I looked, a quarterback doesn't play defense, return kicks or punts, or kick field goals. These pieces of evidence would never enter any serious discussion in terms of statistical evaluation.


My eventual goal is to identify the greatest passer of all time. I will use several statistical measures, many of which are mentioned in this post, to identify the most worthy candidates for consideration. As far as my research is concerned so far, Favre would not make that list. There are several other quarterbacks, not mentioned in this post, nor even displayed in either of the last two graphs that would make more worthy candidates, but that is for a different article.

Is Matt Cassel The New Tom Brady?

Matt Cassel of the New England Patriots is having a good year.  He is 13th in the NFL in Passer Rating, after 14 games.  And, in what may seem eerily similar to one Mr. Tom Brady, he replaced Brady in the first game of the season, when Brady was lost to the season as a result of a leg injury.  Flashback to  September 2001, and the aforementioned Brady, replaced Drew Bledsoe as the quarterback of the New England Patriots.  The rest, as they say, is history.

That year, Tom Brady had a great year.  A dream year.  Replacing Bledsoe in the 2nd game of the season, he went on to lead the Patriots to an 11-5 regular season record, and on to win Super Bowl XXXVI, 20-17 over the St. Louis Rams.  Brady was selected to the Pro Bowl, and was named Super Bowl MVP.  He finished 6th in the NFL in passing, with a Passer Rating of 86.5, and he had a CMI of 0.552 (see the table below).  That year, the league average CMI was 0.497, and his CMI was 1.25 Standard Deviations above the average.  Only Rich Gannon (2.54), Kurt Warner (1.57), and Jeff Garcia (1.33) had a better year that year.  

The graph below the table shows that he started out a little slow (understandably so), and played fairly consistently throughout the year, with a few spectacular (and one not so spectacular) games thrown in.  He didn't throw an interception in his first five games, but then threw 4 in a 31-20 loss at Denver in game 6.  All in all, he didn't throw a pick in nine games, the Patriots going 7-2 in those games.

So, how is Matt Cassel doing trying to imitate Tom Brady?

As mentioned earlier, his current Passer Rating is 87.1, a shade higher than Tom Brady's 86.5.  His CMI is 0.568, also better than Brady's 0.552.  He has six games to-date where he has not thrown an interception, leading the Pats to a 5-1 record in those games.  So how does Cassel's CMI of 0.568 compare to Brady's 0.552?  This is where the comparison ends.  In 2008, the league average CMI is 0.542, so Cassel's performance is 0.49 Standard Deviations above the average.  Good, but not great.  Good for 9th out of 30 quarterbacks who have thrown enough passes to qualify.  The table below shows a game-by-game comparison of Cassel's performances compared to Brady's 2001 season.

Best 25 Seasons in History - CMI

Here's a list of the 25 best seasons in history in terms of CMI.  This list is different than a similar list I published earlier, based on QB Rating.  As I mentioned earlier, when looking at career CMI (versus career QB Rating), this list favors those quarterbacks who didn't throw a lot of interceptions.  What is particularly interesting, is Tom Brady's 2007 season.  He is rewarded on the QB Rating list (#2) for what he did - he threw 50 touchdowns.  He is rewarded here for what he didn't do - he didn't throw a lot of interceptions.  Also, interesting is that, according to this ranking, Peyton Manning had a better 2003 season than he did in 2004 (although he gets a lot of attention for what he did in 2004).  Again, this list is biased towards the more recent years, which of course suggests Sammy Baugh's season in 1945 must have been out of this world.  I will later on, look at these figures, relative to the time periods in which each of these seasons took place. 

Crazy, Debatable and Lucky

Today, the Green Bay Packers lost at home to the Houston Texans, 24-21 on a last-second field goal.  This dropped the Packers to 5-8 for the season, and, for all practical purposes, knocked them out of the playoffs.  I'm sure the Packer faithful will start to think what might have been....

The Packers were coming off a 13-3 season, having won their division handily, and were one win away from the Super Bowl, a loss to the eventual winner, the New York Giants at home.  

Then the soap opera started.  First, Brett Favre, the Packers QB for the past 16 seasons, decided it was time to retire.  The Packers, who had drafted Aaron Rodgers in 2005, were prepared.  During the offseason, the Packers named Aaron Rodgers the starting QB for the 2008 season.  Second, Brett Favre decided he wanted to play in 2008.  Nothing wrong with that.  Only that he had "lost" his starting job to Aaron Rodgers.  No way a future hall of famer is going to be carrying a clipboard for an untested, essentially rookie QB.  Not after the season Favre just had had.  After much ballyhoo, the Packers traded Favre to the New York Jets.  In return, the Packers received a conditional draft pick.  For now, it's a fairly safe bet that it will be at least a second rounder.  The Jets, who finished a lousy 4-12 season, now having found their "saviour", then released Chad Pennington.  Of course, the woeful Miami Dolphins, having just completed a miserable 1-15 season, and desperately needing some talent, promptly picked him up.

So there we have it.  The Packers make a "crazy" move, going with untested Aaron Rodgers, over Hall of Famer Favre.  The Jets, in need of a new direction, trade for Favre and release Pennington in a debatable move.  And the Dolphins, well, got lucky.  Pennington is a dramatic improvement over any Dolphin QB.

Ok, so that's how we all thought about it back in the beginning of the season.  So, let's take a look at how the decisions panned out, in terms of their actual performances.

The table at the top of this article shows each player's stats for the 2008 season, the 2007 season, and their career #s.

First, let's start with Rodgers.

He is having a very good year, despite the team's troubles.  His QB Rating is a robust 92.1 (league average is 85.3), and his CMI is 0.560, about 0.4 standard deviations above the mean of 0.538.  Not bad for being a first-year starter.  Compare him to three other first-year starters here.

Now, let's take a look at Favre.

He had a career year in 2007.  His QB Rating of 95.7 was only exceeded in his MVP years of 1995 (99.5) and 1996 (95.8).  His third MVP year, 1997, his QB rating was 92.6.  Favre's career QB Rating (leading up to the 2007 season) was 85.0.  It has since improved to 85.9 through 13 games of the 2008 season.  In terms of his CMI, 2007 was by far and away, his best year (0.581), eclipsing his previous best of 0.561 in 1995.  Given that it had been a long time since he had put up that kind of #s, it would be reasonable to assume that it wouldn't necessarily continue into 2008.  Well, he's having a (surprisingly) outstanding year in 2008.  His QB Rating is a healthy 88.2, and his CMI is 0.577 (almost as good as last year).  Is he why the Jets have improved?  Hard to say.  Especially, when you take a look at what Pennington has done this year.

Pennington's #s:

Chad is easily having his best year since his first full year in the league, in 1992.  Back then, he produced a QB Rating of 104.2 and a CMI of 0.644.  Only Tom Brady in 2007 (0.647), and Hall of Famer Troy Aikman, back in 2003 (0.645), have had better seasons.  This year, Chad's #s are a QB Rating of 93.7, and a CMI of 0.618.  Compare these to his career #s of 89.7 and 0.578.  By the way, Pennington's career CMI of 0.578 is the all-time career NFL mark.  Next is Steve Young at 0.565.  Pennington's #s are also, needless to say, a dramatic improvement compared to those of the 2007 Dolphins (QB Rating of 67.4, and CMI of 0.484).

So, what does this all mean?  It means that the Packers weren't crazy when they decided to put their faith in Rodgers, the Jets decision is debatable in giving up a 2nd round pick in 2009, and exchanging a QB who, while having an outstanding year, is not doing as well as the QB they gave up on, and the Dolphins got awfully lucky to end up with Pennington.

The 25 Best Seasons by a Quarterback (using current QB Formula)

Here are the 25 best seasons that a quarterback has had in the NFL (since 1940) using the current QB Rating system.  I have previously mentioned my dislike for the system.  However, for now, this is the list.

Note:  This list is slightly different than that shown at The Pro Football Hall of Fame.  The HOF has Bart Starr's 1968 season at #19 with a Rating of 104.3.  I did not include him here as he didn't "qualify", having only attempted 171 passes.  For 1968, I used 14 attempts per game (or, 196 for the season) as the qualifier.