Can you win with mediocre QB play?

In all likelihood, the Vikings will have mediocre quarterback play in 2009. Some people (myself included) think that would have been the case whether or not the team signed Brett Favre, but even the most ardent Sage Rosenfels/Tarvaris Jackson supporters admit they aren't going to turn into Peyton Manning or Drew Brees overnight. With most Viking fans thinking the 2009 version of the team is the strongest in a long time at running the ball and playing defense, the common wisdom is that the only thing potentially holding the team back is the quarterback.

But how much will the quarterbacking hold the team back? There have been plenty of teams, even in the recent, pass-happy NFL, that went a long ways -- and even all the way -- with so-so quarterbacking and a stout defense and/or running game. Recent versions of Baltimore, Chicago, and Tampa Bay teams all spring to mind.

Here are the list of quarterbacks who've acquired Super Bowl rings in the last decade:

Ben Roethlisberger
Eli Manning
Peyton Manning
Tom Brady
Brad Johnson
Trent Dilfer
Kurt Warner

Three of those, I'd say -- Warner, Peyton Manning, and Brady -- have played at an elite level for a good chunk of their careers. Roethlisberger, Eli Manning, and Johnson have been OK-but-not-great, and then there's everyone's favorite whipping boy, Trent Dilfer. That makes over half of the SB-winning quarterbacks of the last decade in the above-average-but-not-great category. Could Sage or Tarvaris fall into this category and maybe play well enough, with a good supporting cast, to take the Vikings to the promised land? Of course, they could -- anything's possible, after all -- but this is still a pretty small sample size to go on and there were several teams that almost made it to the big game, if not for a small blip along the way in the playoffs. If not for the "Tuck Rule" and the "Proehl Rule," we might see Rich Gannon or even Shaun King (!) on this list.

So how good can a team be with iffy quarterbacking? I decided to set the bar of a "good team" as a team that either a) won at least 12 games in the regular season; or b) advanced to its conference championship game (or beyond). That would qualify any team that had a good regular season or a good postseason, at least by most people's definitions, and both criteria would be above and beyond anything the Vikings have done since 2001. Frankly, I'd be happy with that.

60 teams meet these criteria over the last 10 years. I judged their passing prowess both by their team passer rating and their Adjusted Net Yards per Attempt. Here's the list, sorted by passer rating.

Year	Team	PassRate	ANYA
2004	Indianapolis	119.7	8.7
2007	New England	116.0	8.0
1999	St. Louis	106.6	7.3
2005	Indianapolis	103.3	7.3
2001	St. Louis	102.2	6.8
2004	San Diego	102.0	7.0
2006	Indianapolis	101.0	7.4
2003	Tennessee	100.3	7.2
2003	Indianapolis	99.0	6.8
2002	Oakland	97.2	6.5
2007	Dallas	97.1	6.5
2005	Seattle	96.8	6.5
2004	Philadelphia	96.4	6.5
2008	Arizona	96.1	6.5
2007	Indianapolis	96.1	6.5
2007	Green Bay	95.9	6.6
2001	San Francisco	95.0	6.1
2006	New Orleans	94.9	6.9
2000	Minnesota	94.7	6.3
2001	Green Bay	94.1	6.4
2004	Pittsburgh	93.2	5.9
2006	San Diego	93.0	6.3
2004	New England	92.5	6.4
2003	Kansas City	92.4	6.6
2000	Oakland	92.0	6.1
2005	Pittsburgh	89.4	6.1
2005	Denver	88.9	6.3
1999	Indianapolis	88.5	6.4
2005	Jacksonville	88.4	6.0
2006	New England	88.3	5.6
2008	NY Giants	88.2	5.7
2005	Carolina	88.1	5.9
2002	Green Bay	86.6	5.3
2002	Tampa Bay	86.3	5.3
2002	Philadelphia	85.9	5.4
2001	New England	85.3	5.0
2008	Carolina	84.7	6.4
2006	Baltimore	84.6	5.6
2003	New England	84.3	5.4
2002	Tennessee	83.9	5.5
2001	Philadelphia	83.4	5.0
2001	Pittsburgh	83.4	5.6
2000	Tennessee	83.2	5.6
2000	NY Giants	83.1	5.4
1999	Tennessee	83.1	5.7
2008	Baltimore	82.8	5.2
1999	Jacksonville	82.3	5.5
2008	Pittsburgh	81.9	5.1
2008	Philadelphia	81.4	5.4
2007	San Diego	81.3	5.1
2003	St. Louis	81.0	4.9
2003	Philadelphia	80.5	5.1
2003	Carolina	79.6	5.2
2008	Tennessee	78.8	5.5
1999	Tampa Bay	76.5	4.0
2001	Chicago	76.0	4.5
2006	Chicago	73.5	4.7
2007	NY Giants	73.0	4.3
2000	Baltimore	72.7	3.9
2004	Atlanta	72.0	4.1

Super Bowl-winning teams are indicated in bold. The average for this list is 89.3 passer rating and 5.9 ANYA. Surprisingly, for Super Bowl winners, the averages are 87.3 and 5.7. Super Bowl winners were actually worse, on average, than the typical "good team" over this span, at least in terms of quarterbacking!

The last two Super Bowl winners have actually been some of the worst teams at passing the ball, at least in the regular season. Eli Manning had a spectacular 2007 postseason, but Ben Roethlisberger didn't, and, again, that 2000 Baltimore team was laughably bad. We also tend to forget that Tom Brady really wasn't all that early in his career, as evidenced by the so-so showings of his 2001 and 2003 championship teams; those teams were 6th and 1st in points allowed, making Brady more of a "game manager" than a truly elite player in those seasons.

The average league passer rating over this span is somewhere in the high-70s range, so most of these teams at least featured slightly above average passing games, but, with the exception of Peyton Manning's 2006 Colts and Kurt Warner's 1999 Rams, and arguably, Brady's 2004 Patriots, most of the teams to win the big game have featured solid, but not spectacular passing.

Here are some notable quarterbacks' career numbers. Remember that the average QB on a "good" team from 1999 to 2008 had an 89.3 passer rating and 5.9 ANYA:

Brett Favre: 85.4, 5.9
Tarvaris Jackson: 76.5, 5.0
Sage Rosenfels: 81.2, 5.7

Favre's numbers certainly are better than the others', but he's still only about average, or slightly below. Even Jackson and Rosenfels grade out better than Trent Dilfer and Eli Manning in their Super Bowl years. When you take recent events into consideration -- like Favre over the past four years (79.5 passer rating, 5.0 ANYA) and Jackson's late-2008 surge, he looks like even less necessary.

A number of things still need to come together for the Vikings to make an impact this season, but central to all discussion will be the quarterback play. While it would certainly be nice to have a better quarterback situation than what the team currently has, there's (still...still) no evidence to suggest that Brett Favre would have improved the team or even if he was all that necessary to start with. The Vikings have two quarterbacks who, provided they don't completely fall off the wagon, are capable of leading an otherwise-talented team to a good season or even the promised land of the Super Bowl, even if they don't improve much on their career numbers.