Matt Cassel came in and led the team to an 11-5 record and almost to a playoff berth— leading many to label Brady as a product of the Patriots offensive "system" rather than one of the greatest quarterbacks to ever play the game.
However, a closer analysis of the Patriots team performances with and without Brady—particularly on offense—tells a much different story than many would like to believe.
The first point of discussion is the Patriots offensive line. In 2007, they had the most highly regarded offensive line in the NFL. Brady was only sacked 21 times—despite close to 600 dropbacks. Matt Light, Logan Mankins, and Dan Koppen all made the Pro Bowl and started a collective 47 out of 48 possible games.
In 2008, the Patriots offensive line was under criticism for not doing enough to protect Cassel. He was sacked 47 times—despite nearly 50 fewer dropbacks than Brady had in 2007.
What happened? After all, the same three Pro Bowl players were on the left side of the line—so how could they have all of a sudden morphed from extraordinary into average?
Before answering that question, let's look at the 2009 sack totals with Brady back in the lineup. Starting left tackle Light missed five games, and starting right tackle Nick Kaczur missed three games.
With both offensive tackles missing time and a supposedly mediocre offensive line, the Patriots sack totals should have been skyrocketing, right? Not even close—Brady was only sacked 16 times the entire season.
So how can an offensive line go from amazing to mediocre to amazing again? The answer lies in a quarterback's release.
Cassel, on the other hand, has the tendency to hold on to the ball longer and take more sacks—resulting in higher sack totals in 2008 than Brady had in 2007 and 2009 combined.
As an aside, please note that I am not attempting to argue that the Patriots offensive line is the worst in the league and that Brady is the only reason they appear to be good. They certainly are a talented front five. I am only showing how the quarterback is also an important part of whether or not an offensive line gives up plenty of sacks.
That said, let's move on.
2007 (with Brady): 16 games, 98 receptions, 1,493 yards (15.2 YPC), 23 touchdowns
2008 (with Cassel): 16 games, 69 receptions, 1,008 yards (14.6 YPC), 11 touchdowns
2009 (with Brady): 16 games, 83 receptions, 1,264 yards (15.2 YPC), 13 touchdowns
2007 (with Brady): 16 games, 112 receptions, 1,175 yards (10.5 YPC), 8 touchdowns
2008 (with Cassel): 16 games, 111 receptions, 1,165 yards (10.5 YPC), 3 touchdowns
2009 (with Brady): 14 games, 123 receptions, 1,348 yards (11.0 YPC), 4 touchdowns
The statistical difference between Moss in 2008 and his performances in 2007 and 2009 is striking. Even with the questions about his effort in 2009, Moss still performed better with Brady throwing him the ball than Cassel—and the numbers in every category show that.
Why, then, was Welker able to maintain his high stat line—even with Cassel in there? Why didn't he have the same falloff that Moss did? The answer lies in the vastly different styles that the two receivers play.
Welker almost always runs short and intermediate routes; Moss is much more of a vertical threat. As a result, Welker was a more attractive option for the Patriots with Cassel in the lineup—so as to protect Cassel from making the big mistake by forcing the ball down the field.
A similar analysis can be done for Ben Watson, but I will leave that up to the reader.
By far, the most important subject to address is the overall success of the team. At this point, overall records do not tell the whole story, but here they are:
2007 Patriots (with Brady): 16-0
2008 Patriots (with Cassel): 11-5
2009 Patriots (with Brady): 10-6
These numbers do not tell the whole story because the offseason between 2008 and 2009 was one of transition for the Patriots. Several key defensive leaders left through retirement, trade, or free agency—making it appear as though the Patriots were a better team with Cassel.
Another important, but thus far unmentioned, name is Jabar Gaffney. While he might not strike fear into defensive coordinators, he was a solid option behind Welker and Moss in 2007 and 2008 before departing for Denver in 2009.
The Patriots were forced to use a rotation of receivers to replace Gaffney—as opposed to other top passing teams that have at least three solid, consistent, receiving options. The Colts have Wayne, Clark, and Garcon. The Saints have Colston, Moore, Meacham, and Henderson, among others. The Patriots have Moss, Welker, and ????.
However, Brady's greatest importance came in playing playoff-caliber teams. The following are the two quarterbacks' performances against teams that made the playoffs:
2007 Patriots/Brady: 6-0, 1,983 passing yards, 20 passing touchdowns, 3 interceptions, 120.6 quarterback rating
2008 Patriots/Cassel: 2-4, 1,467 passing yards, 7 passing touchdowns, 6 interceptions, 79.9 quarterback rating
2009 Patriots/Brady: 2-3, 1,396 passing yards, 5 passing touchdowns, 4 interceptions, 83.6 quarterback rating
Note the contrast between 2007 and 2008. With most of the same players on the roster, Brady vastly outperformed Cassel against playoff teams. While Brady was very average in 2009 against playoff teams, so was his support. After all, it wasn't Brady who allowed Manning and Brees to pass for a combined nine touchdown passes and allowed the Saints and Colts to score a combined 73 points in two of those three losses.
Finally, let's look at the overall statistical performance of Brady vs. Cassel—which, combined with the analysis above, should be enough to show that Brady is far from just a "system" quarterback.
2007 Brady: 68.9 completion percentage, 4,806 passing yards, 50 touchdowns, 8 interceptions, 117.2 quarterback rating, league MVP
2008 Cassel: 63.4 completion percentage, 3,693 passing yards, 21 touchdowns, 11 interceptions
2009 Brady: 65.7 completion percentage, 4,398 passing yards, 28 touchdowns, 13 interceptions, 96.2 quarterback rating
I hate to break the bubble of the "system" quarterback advocates, but "system" quarterbacks don't toss 50 touchdowns in a season and win league MVPs on a regular basis.
The truth of the matter is that now the Patriots will need Brady more than ever. The Jets are on the upswing, and the Dolphins will have renewed use of the Wildcat offense in 2010 with the return of Ronnie Brown. The Patriots defense is still a work in progress, and there are questions surrounding Welker's knee injury and Moss' age.
However, Brady has been and will continue to be a pivotal part of the Patriots sustained success—and he is a first-ballot Hall of Famer when he decides to call it a career.