In my last post, Tom Brady and Receiver Turnover - Touchdown Edition, I took an in-depth look at the suggestion that by the time Tom Brady retires he will have gone through more personnel changes in the passing game than any Hall of Fame quarterback of the modern era. In this one, I will be looking to try and figure out if the personnel turnover a quarterback faces impacts their passer rating.
First thing is first. Why am I looking at passer rating? Why use such an archaic measure of performance for the study? Well, for that answer I turn to what Kerry J. Byrne writes in his post "Defending traditional passer rating."
The NFL has ALWAYS been dominated by teams that dominate the skies, as measured by passer rating.
• an incredible 40 of 69* NFL champions (58 percent) since 1940 finished the year No. 1 or No. 2 in Passer Rating Differential
• 67 of 69* champions (97 percent) since 1940 finished the year ranked in the top 10 in Passer Rating Differential.
For a little perspective, consider that 68 of 69 champions finished in the top 10 in scoring differential. That's right. Passer rating is nearly as effective at identifying winners as points.
Dominating the skies is important to winning and passer rating is one of the best indicators of passing dominance. Dominating the skies is made easier by when your quarterback is one of the best. But what kind of impact do personnel changes have on quarterbacks that are trying to help their team do so? I wanted to look further into that, but first I needed to change the list of players I was looking at. While Mr. Byrne looks at all champions in history, I am taking the advice of our very own ISN:
What is the "live ball era"? Well, let's go back to Kerry J. Byrne for another helping of NFL history. In "Cold Hard Football Facts: Titans pass defense on pace for record," Mr. Byrne enlightens us to what constitutes as the "live ball era."
By 1977, there was such a dearth of offense that the NFL was forced to institute wholesale rule changes to open up the game in 1978, spawning what we now know as the Live Ball Era.
The NFL also went to a 16-game schedule in 1978. So the rule changes and the longer schedule since then give us the best test group with which to compare the 2008 Titans.
I'm not here to measure the 2008 Titans. However, that last part mentions how the rule changes and longer schedule provide a better test group. I feel like agreeing with this for the sake of my piece. If you recall from my last post, there were 30 quarterbacks tested. I went through and took out every quarterback that did not play the majority of their career in the live ball era. When I say majority, I mean that there will be a quarterback that played some of his career in the previous era. Just so there isn't confusion about who that guy is, it was Dan Fouts whose career spanned from 1973 to 1987.
This cut those 30 quarterbacks down to 15. My freshman year of college stats professor told me that a good sample size for a statistical study needs at least twenty trials. These 15 simply would not do. Where oh where could I find five more quarterbacks for this? I needed to find an answer so I did what any normal person would do. I went to the NFL Career Passer Rating Leaders list on pro-football-reference.com and took the highest names on the list that weren't already in my study. The new additions to the list became Aaron Rodgers, Tony Romo, Philip Rivers, Matt Schaub, and Matt Ryan. Below are their "# of Different Players Per Seasons Played" and "Top 6 WR - TD %." If you are confused by the chart below, please go and read the previous piece which explains how I came to the numbers for each column.
|Player||Total TD||Top 6 TD||Top 6 WR - TD %||# of Players||# of Seasons||# of Different Players Per Season|
A couple things to be noted going forward. Just because these guys are being included in the list does not mean that I am claiming them to be Hall of Fame caliber. Also, I want to reiterate this point from the last piece: THIS IS NOT A RANKING OF QUARTERBACKS.
After taking all of the new quarterbacks in our study and throwing their numbers in with the original 15, the following list was created. The "Average Rank" of the "# of Different Players Per Seasons Played" and "Top 6 WR - TD %" is used to determine which quarterback went through the most personnel changes in the passing game. The more changes a quarterback has gone through, the higher up on the list they are. Accompanying each quarterback is their career passer rating ("PR") and the rank of that passer rating among the quarterbacks in the study ("PR Rank"). The numbers in parentheses are the rank of each of those numbers in that respective list. I included the passer rating ranking separately to make it easier to compare the "Average Rank" and the "PR Rank".
|Player||# of Different Players Per Seasons Played||Top 6 WR - TD %||Average Rank||PR||PR Rank|
|Tom Brady||3.538 (2)||50.898% (2)||2 (1)||96.6||3|
|Brett Favre||3.05 (5)||42.126% (1)||3 (2)||86||14|
|Drew Brees||3.412 (3)||56.173% (5)||4 (3)||94.3||7|
|Dan Marino||3 (6)||51.905% (3)||4.5 (4)||86.4||13|
|Eli Manning||3.111 (4)||63.033% (8)||6 (5)||82.7||16|
|John Elway||2.563 (12)||53.667% (4)||8 (6)||81.6||20|
|Kurt Warner||2.917 (7)||65.865% (10)||8.5 (7)||93.7||8|
|Matt Ryan||3.6 (1)||79.688% (19)||10 (T-8)||90.9||12|
|Jim Kelly||2.909 (8)||67.089% (12)||10 (T-8)||84.4||15|
|Warren Moon||2.412 (14)||59.794% (6)||10 (T-8)||80.9||18|
|Dan Fouts||2.667 (11)||65.748% (9)||10 (T-8)||80.2||19|
|Peyton Manning||2.667 (10)||66.973% (11)||10.5 (12)||95.7||4|
|Joe Montana||2.4 (15)||61.172% (7)||11 (13)||92.3||10|
|Ben Roethlisberger||2.889 (9)||73.545% (14)||11.5 (14)||92.7||9|
|Philip Rivers||2.556 (13)||77.249% (16)||14.5 (15)||94.5||6|
|Troy Aikman||2.25 (17)||71.515% (13)||15 (16)||79.9||17|
|Steve Young||2.267 (16)||75.431% (15)||15.5 (17)||96.8||2|
|Tony Romo||2.111 (19)||77.401% (17)||18 (T-18)||95.6||5|
|Matt Schaub||2.222 (18)||79.167% (18)||18 (T-18)||91.9||11|
|Aaron Rodgers||2 (20)||82.456% (20)||20 (20)||104.9||1|
So after making the study exclusive to only Live Ball Era quarterbacks, the list looks like that. What is interesting is that three of the top five rated passers in the study (Steve Young, Tony Romo, and Aaron Rodgers) were in the bottom four of the list. The other two, Peyton Manning and Tom Brady, were twelfth and first respectively. While this does put four of the top five in the bottom 9, that doesn't really say a whole lot about the connection between passer rating and personnel changes.
Steve Young and Aaron Rodgers, the two highest rated passers of all time, never dealt with much receiver turnover. Young spent the majority of his career throwing touchdowns to Jerry Rice and Aaron Rodgers has played very few seasons in the NFL causing a very high concentration of the same players to account for his total.
Dan Marino and Brett Favre, two that have gone through a lot of receiver turnover, are also two of the longest tenured players on the list. This is no different than Fran Tarkenton having a ludicrous 37.427% "Top 6 WR - TD %" in the previous post. It should also be mentioned that all three of these guys were the all time leader in touchdown passes at one point in their career. Favre broke Marino's record of 420, and Marino broke Tarkenton's record of 342.
If you want this post to have a point so that you don't feel like you've wasted your time, I can give you one. The only quarterback measured in the last two posts to be in the top five of both receiver turnover and passer rating is Tom Brady. While this study did not point to passer rating having an incredible connection to receiver turnover, what it did show is that Brady has had more significant personnel change than the other quarterbacks in the top five in passer rating, as shown below.
|Player||Passer Rating||# of Different Players Per Seasons Played||Top 6 WR - TD %|
As you can see, Brady has been through much more significant personnel changes than the others on the list. Peyton Manning, the closest in both "# of Different Players Per Seasons Played" and "Top 6 WR - TD %", is 0.871 player per season and 16.075% worse than Brady.
I would like to mention that Steve Young's career ended in 1999, a season in which he only played three games before getting knocked out due to concussions, making him the only player on the list that is not currently playing. Peyton Manning is the only one to have played when Young did, and that was only for the 1998 and 1999 season. The other three all started their careers after Young's ended, with Brady getting drafted in 2000 (becoming the starter in 2001), Romo going undrafted in 2003 but debuting for the Cowboys in 2004 (becoming the starter in 2006), and Rodgers getting drafted in 2005 (becoming the starter in 2008). As passing the ball has become considerably easier to do over time, higher passer ratings have become easier to come by for players playing now as well. That said, Steve Young was still fortunate to get to throw the ball to Jerry Rice and Terrell Owens for most of his career.
There isn't much more to this one. I hope you all enjoyed it despite it not coming to many conclusions.This was just one of the directions I wanted to take from that initial idea in the last post. I have another break-down of receiver turnover that I am planning on doing and some completely different ideas I have hidden away somewhere that I can bring out. If you have any questions regarding the methods to my madness, please don't hesitate to ask. Also, if any of my numbers are wrong or you have opinions regarding ways I could look at this better I would love for you to let me know.