In assessing the relative weight of supporting cast vs. the individual performances of quarterbacks in this discussion, especially as it pertains ultimately to post-season success, I believe that team rankings in scoring defense and rushing offense are particularly enlightening. This will be lengthy, so I will post in two separate communiqués, the first of which analyzes scoring defense. Beginning with 2001, when Brady became the starting quarterback for New England, we see the following:
2001: NE (6th), 272 points; INDY (31st), 486 points. NE wins Super Bowl. INDY finishes 6-10.
2002: NE (17th), 346 points; INDY (7th), 313 points. INDY finishes 10-6, NE 9-7.
2003: NE (1st), 238 points; INDY (20th), 336 points. NE wins Super Bowl. INDY finishes 12-4.
2004: NE (2nd), 260 points; INDY (19th), 351 points. NE wins Super Bowl, INDY finishes 12-4.
2005: NE (17th), 338 points; INDY (2nd), 247 points. INDY finishes 14-2, NE finishes 10-6.
2006: NE (2nd), 237 points; INDY (23rd), 360 points. Both teams finish 12-4. INDY wins Super Bowl.
2007: NE (4th), 274 points; INDY (1st), 262 points. NE finishes 16-0, INDY finishes 13-3.
2008: NE (8th), 309 points; INDY (7th), 298 points. NE finishes 11-5, INDY finishes 12-4. Brady was injured in opener and missed the rest of season.
2009: NE (5th), 285 points; INDY (8th), 307 points. NE finishes 10-6, INDY finishes 14-2.
2010: NE (8th), 313 points; INDY (23rd), 388 points. NE finishes 14-2, INDY finishes 10-6.
2011: NE (15th), 342 points; INDY (28th), 430 points. NE finishes 13-3, INDY finishes 2-14. Manning misses entire season.
2012: NE (9th), 331 points; Denver (4th), 289 points. NE finishes 12-4, Denver finishes 13-3.
2013: NE (10th), 338 points; Denver (22nd), 399 points. NE finishes 12-4 and Denver finishes 13-3.
What can we conclude from this data? New Englands three Super Bowl victories during the Brady era were supported by defenses that ranked 6th, 1st and 2nd, respectively. Peytons one Super Bowl ring, on the other hand, is a true statistical outlier; it was won despite a defense that ranked 23rd in scoring defense.
Brady has never played with a defense ranked lower than 17th in this category; he has enjoyed the support of ten top 10 defenses and 6 top six defenses. From 2001 until the present, the Patriots average defensive ranking in this category has been 7.9.
Defensive rankings of teams that Peyton has quarterbacked have been much more variable. Their average ranking throughout this period has been 15th, but this does not begin to tell the whole picture. Peyton has enjoyed the support of six top ten defenses and three top five defenses; he also has been saddled with six defenses, including the present one, which have ranked 20th or lower in scoring defense.
The 49ers during Montanas era were even more consistently dominant on defense than the Patriots, with Brady at the helm:
1981 (Montanas first full year as starter): 2nd (250 pts.). SF wins Super Bowl.
1982 (23rd in the strike-shortened nine-game season), 206 points. 3-6 record.
1983 (4th), 293 points. 10-6 record.
1984 (1st), 227 points. SF is 15-1, wins Super Bowl.
1985 (2nd to the other-worldly Chicago Bears defense), 263 points. 10-6 record.
1986 (3rd), 247 points. 10-5-1 (Montana played only eight games).
1987 (3rd), 253 points. 13-2 record (Montana started only 11 games).
1988 (8th), 294 points. 10-6 regular season, SF wins Super Bowl.
1989 (3rd), 253 points. 14-2 regular season, SF wins Super Bowl.
1990 (2nd), 239 points. 14-2 regular season.
So, as phenomenally as Montana played in his Super Bowl appearances, he also had the 2nd, 1st, 8th and 3rd best scoring defenses, respectively, at his back.
All data were excerpted from
Pro-Football-Reference.com - Pro Football Statistics and History.
All of this really makes you appreciate more fully what Peyton has accomplished as an NFL quarterback. He has been dealt a hand more comparable to that of Dan Marino than Tom Brady or Joe Montana, i.e. excellent skilled position players and, for the most part, mediocre defenses.
There is no question that Montana and Brady were/are extraordinary quarterbacks. However, it can be argued that there is also a certain "McCarron effect" here as well. When you have a consistently strong defense at your back, you can afford to be highly efficient and resist the temptation to make risky, gunslinger-like throws a la Marino or Favre. Because of the hit-or-miss nature of defenses he has played with, Peyton has had to directly shoulder more of the responsibility for the success of his teams than Brady or Montana has over the course of their careers. You can nitpick as to who individually is the better clutch performer over various portions of their respective careers, but you can also find supporting evidence here for the oldest fundamental truth in football. Even when you are talking about QBs as great as these three, defense wins championships.