Who's Better, Who's Best - Manning, Favre and Brees

Last Sunday we were all treated to some good football.  The AFC Championship featured the surprising NY Jets, against the Peyton Manning-led Indianapolis Colts, and the NFC Championship showcased the Drew Brees-led New Orleans Saints who played host to Brett Favre and his Minnesota Vikings.


Not only are these outstanding football teams, but three of the four teams featured three of the game's best quarterbacks in Manning, Favre and Brees.  I thought it would be illustrative to take a look at each of the three quarterbacks individually, and then compare the three side by side to get a sense who maybe better, and perhaps even, who may be best.  In evaluating their relative merits, I will only consider their ability to throw the football, not win games, or how well they run, or whether they are clutch performers, or how many Super Bowl victories they have.


Here are the career NFL Passer Ratings for these quarterbacks:

Manning is clearly the best.  Well, at least that's what looking at the career NFL Passer Rating will tell you.  These figures differ from what you would find at the Pro Football Hall of Fame (as of January 23rd, 2010).  The reason being that the figures listed on the Pro Football Hall of Fame site were as of the beginning of the 2009 season, and mine are as of the end of the 2009 season just completed.

For reasons that I have chronicled in the past (see here, here, and here), the NFL Passer Rating formula is in and of itself is of little use in determining who among the three might be best.  The three quarterbacks very well might end up being ranked this way when it is all said and done, but that doesn't justify the rating system.

In order to complete our analysis, we have to make several adjustments to the NFL's passer rating system.  

The first, is that we need to take each player's passer rating, and relate it to some baseline, so that we may account for players playing in different eras (yeah, I know, it's a little bit odd to be talking about players in different eras when comparing three current quarterbacks, but Brett Favre has been throwing since 1992, and Drew Brees only since 2002.  And since the average NFL passer rating has been increasing over time (see here), we need to make an adjustment for that.  The method that I have chosen is to relate a given quarterback's performance relative to the mean for that year, and use the standard deviation in that year as the measuring stick.  In other words, the difference between the quarterback's actual performance compared to the mean, as a function of the standard deviation.  As I described here, we then convert each of these resulting measures, also called z-values, into percentile ranks, using the standard normal distribution.

The second, is that we need to account for the fact that they've each played a different number of seasons.  While I used a rather simplistic approach last year, I will present a more sophisticated approach starting with this blog.  This method will need further refinement over time, since I am early in my thought process regarding this particular topic.  However, it is an improvement over last year's simplistic approach.  Actually, the method used last year (average deviation) really doesn't take into account the number of years at all.  When I evaluated Brett Favre's career, I simply compared him to a group of quarterbacks who had played a like number of years, and simply ignored any comparisons to players who played far fewer seasons.  That method won't work in this case, as we need to compare three quarterbacks with three vastly different career lengths.  All else being equal, and they rarely, if ever, are, a player who has a 10 year career versus a player who has a 7 year career should get a higher rating (even if, and especially if, they both had the exact same ratings in every year they played).  But the question becomes, "how much higher"?

The third, is that we need to somehow account for the fact that each of the three quarterbacks has played not only a different number of seasons, but that those seasons represent different parts of their careers.  In some respects, since the last 8 seasons have been common to all three, we could simply look at the last 8 seasons.  But, that would mean that we would be comparing Brett Favre in his 11th through 18th seasons, Peyton Manning through his 5th through 12th seasons, and Drew Brees his first 8 seasons.  As I have shown in the past, the early years for a quarterback tend to be the "learning years", and hence this comparison would be inappropriate without the proper adjustments.  Brett Favre is also 40 years old, and we have seen declining performances as quarterbacks age (actually, their performances increase at first as they gain experience, and then subsequently decline as the physical toll takes effect).  One method is to look at each player's first 8 years, since in that case the comparisons would be over the identical portions of their careers.  And perhaps we could compare Favre and Manning for the first 12 years.

Last, we need not assume that the NFL Passer Rating is the measure to be used to evaluate who might be the better passer.  The NFL Passer Rating system has a lot of flaws.  I will use two measurement methods.  The first is the concept of Adjusted Passer Rating.  As I have previously mentioned, the average NFL Passer Rating has been steadily increasing every year.  The Adjusted Passer Rating normalizes the passer rating so that the average for each year is 66.7.  This is then very helpful in evaluating players who played in different years (such as the case here).  Last year, I introduced a simple measure of passing efficiency - CMI.  I now call this CMTI (or, simplistically, Completions Minus Thrice Interceptions).  It is not only simple, but it has a 86% correlation with the NFL Passer Rating.  And, because it is so powerful in explaining any variances in the NFL Passer Rating, and because it is so easy to compute, use and explain, I will use it here.

So, to recap, we will make the following adjustments:

1. Relate performance in given year to the mean, and then in relation to standard deviation for that year - then convert to percentile rank
2. Use a 'better' measure than NFL Passer Rating.  We will show that Adjusted NFL Passer Rating is 'better', and CMTI is simpler
3. Take into account differing number of seasons played by each quarterback
4. Take into account quarterbacks who are at different stages of their career

Here are the respective #s for each quarterback by season:

Brett Favre

Drew Brees

Peyton Manning

What do these performance measures say?  Well, there's a lot of information here, so let's take these one at a time.


The first is that the career averages shown (actually all of the averages shown) are simple arithmetic averages of each of the years, not a true weighted average.  You can see that these simple averages are close enough to the true average by looking at the career average NFL passer ratings shown in these three exhibits and compare them to the career average for each of the quarterbacks shown earlier.


The second is that regardless of what measure we use, whether it is the NFL Passer Rating, Adjusted NFL Passer Rating, CMTI, first 8 years, last 12 years or what not, it should be very clear that Peyton Manning has performed at a truly superior level compared to the other 2 players (or anyone else for that matter).  Just look at CMTI over the past 8 years, for example.  He has averaged being in the 90th percentile over the past 8 years.  Basically, that suggests that he is, on average, in the Top 3 every year.  Truly remarkable.  In Peyton Manning, we are watching one of the all-time best.  A once-in-a-generation quarterback.  In case you didn't notice, the rows highlighted in green indicate a performance that is in the 85th percentile or higher.  The areas in blue are 95th percentile or higher.


Ok,  Manning is best.  That was easy.  Now comes the difficult part.  Who's better, Favre or Brees?


The case for Favre:


On an Adjusted Passer Rating basis, Brett Favre's first 8 years are comparable to, if not better than Drew Brees' first 8 years (70th percentile versus 68th percentile).  We can't directly compare their two careers since one has had an eighteen year career while the other only eight.  It is very evident that, but for the last year, Favre's performance has been quite pedestrian over the past 10 years.  Well, we can't necessarily penalize him for that, because we don't know how Brees might do in his next 10 years.  We don't even know if he is likely to play another 10 years.  Given history, however, it is fairly safe to assume that he won't play another 10 years.  In my database, going back to 1932, and including both the AAFC in the 1940's as well as the AFL in the 1960's, I have a total of 416 quarterbacks who qualified in at least 1 year.  206 of these quarterbacks qualified in only 1 or 2 years.  The average is 4.125 years.  There are only 6 quarterbacks that qualified in 15 or more years.  Y.A. Tittle qualified in fifteen different seasons.  John Elway, Dan Marino and Johnny Unitas each qualified in sixteen different years.  And then there are the ultimate marathon men, Fran Tarkenton and Brett Favre, who both qualified on 18 different occasions.


Michael J. Schell, in his book Baseball's All-Time Best Hitters, makes an adjustment to player batting averages, called a late-career adjustment.  In essence, he recognizes that a player's performance declines as he ages, and so he makes an adjustment for it.  Schell basically caps the at-bats of a player at 8,000.  All at-bats beyond 8,000 are ignored.  This way, he can compare each player through their first 8,000 at-bats.  Doing that type of adjustment would be extremely difficult in the case of football.  We know that the average number of passes attempted by a player per game has increased over time (see here and here), so limiting to a fixed number of attempts would be difficult and meaningless at best.


We could limit the player performances to a given number of seasons.  Look at the three graphs below.

The first is the average percentile rank of CMTI for all 416 quarterbacks by age.


And the second is the same as the first, except with the x-axis denoting the number of seasons in which they qualified instead of their age.


It appears that there is a learning curve at first (and an elimination process, as presumably the worst players end up having shorter careers), followed by a decline after about 12 years.  Keep in mind that this first graph shows the career percentile rank.  What we're really interested in is does performance decline as a player ages?  So, what we really want to see is the average percentile rank for a given year of a player's career no matter how long they have played.


This is what the third graph shows.  It's actually a bit surprising.  There doesn't appear to be a significant drop-off.  As a matter of fact, out in the 15th-18th years, their performance seems to have got better!  Ok, so in the outer years, we're not talking about a lot of players (for years 17 and 18 its just 2 players - Tarkenton and Favre), so anomalies should be expected.  So what do we do?


I mentioned earlier that the average number of years in which a quarterback qualifies is 4.125 for all 416 quarterbacks.  The table below shows the data in more detail.

There are a total of 77 quarterbacks who have played (qualified) in 8 or more years.  That would be 77/416 = 18.5% of the eligible list.  The average number of years for this group is 10.8, and the median number of years for this group is 11.  It would seem reasonable then to look at a minimum of 8 years as a cut-off.  But how do we recognize players who have played a lot longer?  The method that I have chosen is to look at a given player's best 8 years.  This means several things.  First, the obvious - it eliminates from consideration any player who has qualified in fewer than 8 years.  Second, it accounts for the fact that players have played longer, and, that fact doesn't hurt them.  As a matter of fact, it's the opposite.  The less a player has played, the more the "penalty".  Third, given the small sample of players playing beyond 14 years, it is quite possible that one or more of them had good years in those later years, so why exclude those years?


So, going back to the tables where I showed each of the three quarterbacks and their individual seasons, you can see that Favre's best 8 years are better than Brees' 8 years.  This gives credit to Favre's lengthy career.  Remember, less than 20% of the qualified quarterbacks even get to 8 years total, let alone be fortunate enough to have 8 good years.  Perhaps over time, Brees might very well exceed Favre.  And, if and when he does, we'll give him credit for it at that time.


The case for Brees:


Although comparable to Favre in his first 8 years based on Adjusted Passer Rating, using CMTI gives Brees the nod.  Also notice that Brees has had four years where he was better than 85th percentile, while Favre only had one.  Brees' last four years in New Orleans have been especially strong.  In each of years 5-8, Brees outperforms Favre, while in the first four, Favre outdoes Brees 3 out of four years.  Favre, it appears, built his legend largely on the success of his first year, and perhaps even starting with his first game.  Check out the following chart.

It shows the average percentile rank for all quarterbacks who played longer than 8 years, for each year they played.  Actually, it's not quite the number of years they played in as much as it is the number of years in which they threw enough passes to qualify to have a rating.  It's the blue line, and it includes data from the previously mentioned group of 77 quarterbacks.  The blue line in this graph is different than the line shown on the third graph earlier, in that this only includes data for those quarterbacks qualifying in 8 or more years.  The red line is the data for Drew Brees.  The green line is the data for Favre.  Clearly, outside of his first year, and then his 3 MVP years (years 3-5 for him), Favre hugged the average for this group of quarterbacks.  Some years he did better, and some he did worse.


We're almost done.  One more graph.

This one puts a slight twist on the notion of the best years.  Instead of just looking at the best 8 years, why don't we look at the best n years, for each year n that the quarterback has played.  So this way, we can look at the best year for each quarterback, the best two years, the best three years, and so on.  For good measure, I also threw in Manning's #s.


So what do we conclude from all of this?


Again, if there, was any doubt before, this should put it to rest.  Manning is clearly the best.


Between Favre and Brees, an argument could be made for either.  In terms of a total career, Favre gets the nod, simply because of the number of years he's played.  Brees has put up some impressive numbers so far.  If he continues this for a few more years, he will most likely finish ahead of Favre, but that remains to be seen.  Based on the evidence so far however, he is doing at least as well as, if not better than Favre did in his first 8 years.  Perhaps we'll check-in in a few years when Brees retires.  And, speaking of retirement, in my next post, I'll take a look at Kurt Warner's career.

Quarterbacks and the NFL Draft - Part 5

This post is the corollary to the previous post.  That is, we will attempt to answer the following question: which quarterbacks drafted in the past 30 years turned out to be the biggests busts?  Naturally, these would be the quarterbacks drafted with really high expectations - those that were drafted in the first round, or better yet, drafted in the Top 10, or even better, #1 overall, perhaps.  These cases of buyers remorse are further exacerbated when quarterbacks taken later (much later in some cases) turn out to have far superior careers.  

The list you see below, along with the list in my previous post, should illustrate the difficulty of identifying who might be the best NFL quarterbacks before their first game.  It is certainly an inexact science.  It is why I question the merits of a) picking a quarterback so early in the draft, and b) paying them such large sums of money before they ever throw a pass.  I will explore these questions in my next post.  

In the meantime, here's my list of the 10 quarterbacks who were the biggest busts of the NFL Draft over the past 30 years.  Unlike the biggest surprises, this list is a bit more difficult to assess.  For the surprises, one merely looks at the relevant statistics, and then finds an appropriate weight (for example, how much weight to assign to longevity).  For the busts, how does one quantify those that don't play (or don't play enough).  In my system of quantifying quarterback passing statistics, one must throw enough passes in a given season to qualify to be ranked (in other words, I don't rank every player that threw a pass as that would be meaningless).  For that reason, I shall merely list the players, and not rank them, starting with the earliest drafts.

The List

Jack Thompson (1979, 1st Round, 3rd Overall Pick, 1st Quarterback Drafted) - Thompson was drafted out of Washington State by the Cincinnati Bengals.  He was taken ahead of Phil Simms (7), and Joe Montana (82).  He qualified in 1 year.  He makes the list not because of his statistics as much as he was drafted so far in advance of the the quarterback who arguably was the greatest passer of all time.

Rich Campbell (1981, 1st Round, 6th Overall Pick, 1st Quarterback Drafted) - Campbell was drafted out of The University of California by the Green Bay Packers.  He was taken ahead of Neil Lomax (33).  Campbell didn't attempt enough passes in any year to qualify, and threw a total of 68 passes in two different seasons.

Art Schlichter (1982, 1st Round, 4th Overall Pick, 1st Quarterback Drafted) - Schlichter was drafted out of Ohio State by the Baltimore Colts.  The Chicago Bears selected Jim McMahon (5)  out of Brigham Young one pick later.  What bust list would be complete without Schlichter, known more famously for his gambling addictions.

Todd Blackledge (1983, 1st Round, 7th Overall Pick, 2nd Quarterback Drafted) - Blackledge was drafted out of Penn State by the Kansas City Chiefs.  Quarterbacks taken after Blackledge that year include Jim Kelly (14), Tony Eason (15), Ken O'Brien (24) and Dan Marino (27).  Todd qualified in 1984, a year when he completed 50.0% of his passes and had 3.7% of his attempts picked off.  John Elway was drafted 1st Overall that year.  Elway, Kelly and Marino are all in the Pro Football Hall of Fame.

Kelly Stouffer (1987, 1st Round, 6th Overall Pick, 2nd Quarterback Drafted) - Stouffer was drafted out of Colorado State by the St. Louis Cardinals.  Notable quarterbacks taken after Stouffer in that year's draft includes Jim Harbaugh (26), Rich Gannon (98) and Steve Beuerlein (110). Stouffer did not attempt enough passes in any given year to qualify, and threw a total of 437 passes over the course of four different seasons.

Heath Shuler (1994, 1st Round, 3rd Overall Pick, 1st Quarterback Drafted) - Shuler was drafted out of Tennessee by the Washington Redskins.  He qualified in 1 year (in 1994), when he completed 45.3% of his passes, and had 4.5% of his passes intercepted, a poor enough performance to be -2.54 standard deviations below the mean.

Ryan Leaf (1998, 1st Round, 2nd Overall Pick, 2nd Quarterback Drafted) - Leaf was almost picked by the Indianapolis Colts.  Instead, they went with some fellow named Peyton Manning.  The San Diego Chargers drafted Leaf out of Washington State.  Successful quarterbacks drafted following Leaf that year are Brian Griese (91) and Matt Hasselbeck (187).  In 2000, Leaf completed 50.0% of his passes, and had a 5.6% interception rate, a performance so poor it was -2.81 standard deviations below the mean.

Tim Couch (1999, 1st Round, 1st Overall Pick, 1st Quarterback Drafted) - Couch was drafted out of Kentucky by the Cleveland Browns.  That year, the following quarterbacks were also drafted.  Donovan McNabb (2), and Daunte Culpepper (11).  Couch played enough to qualify in 3 seasons with an average standard deviation of -0.58.  His best year was in 1999, when he finished when he completed 55.9% of his passes, and had 3.3% intercepted, good for -0.42 standard deviations below the mean.

Akili Smith (1999, 1st Round, 3rd Overall Pick, 3rd Quarterback Drafted) - Smith was drafted out of Oregon by the Cincinnati Bengals.  Donovan McNabb was taken 1 pick ahead of him, and Daunte Culpepper was taken 11th that year.  Smith qualified in 1 year (in 2000) when he completed just 44.2% of his passes and 2.2% picked off, sufficient to be -2.10 standard deviations below the mean.

Alex Smith (2005, 1st Round, 1st Overall Pick, 1st Quarterback Drafted) - Smith was drafted out of Utah by the San Francisco 49ers.  Although still a little early to be evaluating this draft, a couple of quarterbacks that were taken subsequent to Smith are Aaron Rodgers (24), and Jason  Campbell (25).  Smith has qualified in 1 year (2006), when he completed 58.1% of his passes and had 3.6% of his attempts intercepted.  He finished that year -0.61 standard deviations below the mean CMI.

That's a who's who of busts and disappointments.  I could name another dozen or so who arguably could make this list, but we must draw the line somewhere!

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.

Stat of the Week - #1

I'm introducing a new feature - Stat of the Week - little or no commentary - just a stat - mostly because I'm not sure I'll be able to post a blog every week because a) I love my day job, and that takes a lot of my time, and b) posting, especially an interesting, well-researched post, takes time, and I'm just not sure I have the time to do a detailed post every week.  So enjoy....

Highest Career CMI

The two tables below show the Top 100 quarterbacks in terms of their career CMI. Surprising? Well, it should be. It doesn't meet with your expectations. Chad Pennington the best quarterback in history, terms of CMI. Well yes. And no. Keep in mind that Chad Pennington is no slouch - he has the 8th best all-time career QB Rating. As a matter of fact, the quarterbacks who have top 10 highest QB Ratings in history, are in the Top 10 in terms of CMI.


I have shown before, that CMI has been steadily increasing over time. So obviously, QBs in more recent years have had higher CMIs than earlier quarterbacks. But the list below does give us a different picture of the top quarterbacks in history compared to a similar list ranked by QB Rating.


CMI does not reward quarterbacks that throw a lot of touchdowns per se (see Dan Marino). It does reward quarterbacks that do not throw a lot of interceptions (see Troy Aikman). Think about the teams that these two quarterbacks played on. Dan Marino never had a quality running back for an extended period of time. Troy Aikman had, well, Emmitt Smith, he of the NFL-record 164 career rushing touchdowns. CMI doesn't penalize a quarterback for sharing the backfield with a good running back.


My goal is to eventually identify the best passers in history, using CMI. The way to do it (in order to account for the ever increasing average CMI), is to relate each quarterback to his peers. I am currently working on methodology that can do this "properly".

Best Quarterbacks in History (in terms of current QB Rating Formula)

Here are the Top 50 quarterbacks all-time, based on QB Rating.  I only considered those with at least 1,500 pass attempts (and there were 142 in all over the course of history that had at least 1,500 attempts).  Data is only through the full 2007 season.  I will update this list following the end of the 2008 season.  One can clearly see the bias favoring the modern quarterback.

Here's the next 50.  One needs to look at this list if you wanted to see QB's from yesteryear.

So, it begs the question, does the QB Rating system need to be changed so that fair comparisons can be made over time?  After all, the methodology behind it indexes the statistics to the 1972 season.