Years of studying the data and carving out the marble statue of analytical wisdom that is the Cold, Hard Football Facts have taught us to always turn to the quarterback when looking for the difference between victory and defeat.
Teams win when quarterbacks play well. Teams lose when quarterbacks play poorly. It's as steady and sure as our daily drinking habit.
Oh, sure, we realize that quarterbacks don't play in a vacuum and that many other factors are involved in wins and losses at the end of the day. But there's no doubting that the quarterback is the lynchpin of success in any pro football organization.
There's also no doubting that your team's hopes – so bright and giddy as we enter training camp – hinge largely on the play of its quarterback.
So here's our take on the Great 8 – the eight best quarterbacks in the game today, the eight quarterbacks most likely to give their team a shot at Super Bowl success in 2009. We use team-wide success as a primary consideration because quarterbacking is not just about stats (least of all passing yards). It's also largely about winning. The greatest quarterbacks are typically the greatest winners. Fair or not, that's the deal.
There are a couple notable omissions from our Great 8: Joe Flacco and Matt Ryan, for example, are bright young quarterbacks and both lifted their teams to the playoffs as rookies last year. But it's hard to properly gauge their careers after just a single season. Check back next year, and they both may be very high on the list. In fact, we're very high on both of them. Or maybe that's the helium talking. But it's merely a lack of evidence to make judgments either way at this point.
Cowboys fans will be apoplectic to find that Tony Romo is not on the list, either. He's had a short but spectacular regular season career – with a Peyton-esque 94.7 passer rating, one of the best marks of all time, to show for it. But the jury's still out Romo until the Cowboys actually win a playoff game. He's also still short of the 1,500 pass attempts required to qualify for official NFL records, so he really still is very inexperienced. Plus, Terrell Owens is a huge difference maker for every quarterback he's played with. And we have a very strong suspicion that Romo will not put up the same amazing numbers now that T.O. is plying his trade in Buffalo.
So, here goes:
8. Donovan McNabb
Type of Quarterback: The Great Protector 
Career: 2,534 of 4,303, 58.9%, 29,320 yards, 6.8 YPA, 194 TD, 90 INT, 85.9 rating
Best year: (2004) 300 of 469, 64.0%, 3,875 yards, 8.3 YPA, 31 TD, 8 INT, 104.7 rating
Last year: 345 of 571, 60.2%, 3,916 yards, 6.9 YPA, 23 TD, 11 INT, 86.4 rating
The Cold, Hard Football Fact: McNabb is the least intercepted passer in pro football history (2.09% of attempts).
The straight dope: Why have the Eagles consistently won in the Donovan McNabb Era? One of the biggest reasons is that McNabb keeps the ball out of the arms of opposing defenders – and all CHFF readers know that passers who don't throw INTs win football games.
McNabb had his greatest statistical season during the T.O. honeymoon of 2004 in Philly. It's no coincidence that his most productive season was also the lone season the Eagles reached the Super Bowl during a decade in Phi-Town. You might remember, though, that the Eagles lost that night as McNabb lost his lunch on the field. Hey, these things happen.
Philly management added a few more receiving weapons to the arsenal last year for the first time since the TO divorce, and the 32-year-old McNabb responded with a career best 3,916 yards and once again brought the Eagles to within a game of the Super Bowl, where they lost to Arizona.
The Eagles are  now 1-4 in title games under McNabb. In fact, a failure to get over the hump might go down as what Philly fans remember most about their potential Hall of Fame quarterback.
To use a glass-half-full outlook, the Eagles have been the NFC's most consistent winners since McNabb rode into town. And only Tom Brady has more postseason experience (17 games) than McNabb (15) among active quarterbacks. McNabb also played very well last year in the playoffs – even in the title-game loss to the Arizona, he passed for 375 yards, 3 TD and a 97.4 passer rating.
Outlook for 2009: The Eagles should continue to compete for NFC titles as long as the tandem of McNabb-Reid stick together and as long as McNabb protects the football. It's gotta break for them sooner or later, doesn't it?
7. Drew Brees
Type of Quarterback: Modern Gunslinger
Career: 2,334 of 3,650, 63.9%, 26,258 yards, 7.2 YPA, 168 TD, 99 INT, 89.4 rating
Best year: (2004) 262 of 400, 65.5%, 3,159 yards, 7.9 YPA, 27 TD, 7 INT, 104.8 rating
Last year: 413 of 635, 65.0%, 5,069, 8.0 YPA, 34 TD, 17 INT, 96.2 rating
The Cold, Hard Football Fact: Brees is the only quarterback in history to pass for 4,400-plus yards in three straight seasons.
The straight dope: Brees went a long way toward improving his reputation last year with just the second 5,000-yard passing season in NFL history. He fell just 15 yards shy of Dan Marino's record 5,084 passing yards.
But the similarities between the two seasons ends there:
  • Marino averaged 9.0 YPA. Brees averaged 8.0.
  • Marino threw 48 TD and 17 INT. Brees threw 34 TD and 17 INT.
  • Marino's Dolphins scored 513 points. Brees' Saints scored 463.
  • Marino's Dolphins went 14-2 and won the AFC title. Brees' Saints went 8-8 and finished in last place in the NFC South.
Still, there's no shame in failing to match the standards of Marino '84. Few if any ever have. Plus, Brees has topped 4,400 passing yards for three straight seasons – a mark unmatched in NFL history. But you know how we feel about the emptiness of passing yards, and Brees provides further evidence. Only one of those three seasons ended with a winning record (Saints went 10-6 in 2006).
But paired with a half-decent defense last year, the Saints very well could have won the NFC South and made some noise in the playoffs (Marino, for his part, played with a very solid defense in 1984; the 2008 Saints surrendered 393 points). The same can be said here in 2009: Brees needs some help from the defensive side of the ball.
The outlook for 2009: Brees has proven he's an elite passer. Now he must prove he's an elite quarterback. You do that in the NFL by winning and then by winning playoff games. Brees is 1-2 in the postseason in his seven years as a starter with San Diego and New Orleans.
6. Chad Pennington
Type of Quarterback: Pigskin Precisionist 
Career stats: 1,580 of 2,395, 66.0%, 17,391 yards, 7.3 YPA, 101 TD, 62 INT, 90.6 rating
Best year: (2008) 321 of 476, 67.4%, 3,653 yards, 7.7 YPA, 19 TD, 7 INT, 97.4 rating
Last year: 321 of 476, 67.4%, 3,653 yards, 7.7 YPA, 19 TD, 7 INT, 97.4 rating
The Cold, Hard Football Fact: Pennington is the most accurate passer in pro football history, with a 66.0 career completion percentage.
The straight dope: Pennington is not considered an elite QB by anybody but the Cold, Hard Football Facts. The bottom line is that his teams have won when he's played, and he has put up some great numbers. In fact, the list of quarterbacks in NFL history with a better passer rating is a short one: Young, Manning, Warner, Brady and Montana. That's it, folks.
The problem, of course, is that injuries have interrupted too many seasons for him to be remembered by most as a great quarterback.
But Pennington vindicated himself as one of the league's best quarterbacks last year, when he was the single biggest reason for the single biggest one-season turnaround in NFL history. The Dolphins rose from 1-15 in 2007 to 11-5 and AFC East champs in 2008. Whenever you see a team improve so quickly, it can almost always be attributed to an improvement in the passing game. And no unit in all of football improved more dramatically from 2007 to 2008 than the Miami passing game.
Sure, Miami had a big injection of new names and faces from top to bottom last year. But none of it matters if your quarterback plays poorly. The improvement in Miami's passing game, meanwhile, was truly stunning. In fact, Pennington should have won league MVP honors last year for leading the greatest single-season turnaround in league history. If not for the Peyton Manning worship that infects the football media like a bad case of jock itch, Pennington would have won the award easily.
Pennington has even had a couple of nice playoff moments in his career: he was brilliant with the Jets in a 41-0 destruction of the Colts in the 2002 playoffs; and played extremely well in New York's shocking 20-17 win at San Diego in the 2004 playoffs.
The outlook for 2009: Pennington needs a deep run into the playoffs with Miami for the pigskin public to finally accept him as one of the better QBs in the game. He also has a chance to prove that 2008 was no fluke and that the Dolphins are in fact ready to consistently challenge the Patriots as beast of the AFC East.
5. Philip Rivers
Type of Quarterback: Steam Shovel of Efficiency/Stat Monster hybrid
Career stats: 890 of 1,428, 62.3%, 10,697 yards, 7.5 YPA, 78 TD, 36 INT, 92.9 rating
Best year: (2008) 312 of 478, 65.3%, 4,009 yards, 8.4 YPA, 34 TD, 11 INT, 105.5 rating
Last year: 312 of 478, 65.3%, 4,009 yards, 8.4 YPA, 34 TD, 11 INT, 105.5 rating
The Cold, Hard Football Fact: Rivers currently boasts the same career passer rating as Tom Brady (92.9).
The straight dope: After a few years of displaying flashes, Rivers emerged as an elite NFL quarterback last year, leading the league in TD passes, YPA and passer rating and leading the Chargers to 27.4 PPG (second) and to an unusual AFC West title with a mere 8-8 record.
In his first season as a starter (2006), the Chargers went 14-2. In his second, they went 11-5 and played for the AFC title before losing to the undefeated Patriots. In his third, the Chargers won the AFC West and went toe-to-toe with the eventual Super Bowl champ Steelers in Pittsburgh, before finally bowing, 35-24.
In that Steelers game back in January, Rivers passed for 308 yards, 3 TDs and a 105.4 passer rating against one of the best pass defenses the NFL has produced in years.
That's a pretty good track record.
Rivers also boasts a career passer rating of 92.9. If that number sounds familiar, it's because it's also Tom Brady's career passer rating – good enough for fourth best all-time. (Rivers, however, needs 72 attempts to qualify for official NFL records – min. 1,500 attempts – which he should reach in Week 2 or Week 3).
Rivers, in other words, has put together a pretty good career for himself. The problem, of course, is that the other two big-name members of the QB Class of 2004 – Ben Roethlsberger and Eli Manning – already boast nice shiny Super Bowl rings.
The outlook for 2009: From the days of John Hadl, through the days of Dan Fouts, and through today, the Chargers organization has a long history of great regular-season offenses that never seem to come through in the playoffs. Rivers can change this history, and establish himself as a Top 4 NFL quarterback, with a Super Bowl run.
4. Peyton Manning
Type of Quarterback: Prolific Stat Monster
Career: 3,839 of 5,960, 64.4%, 45,628 yards, 7.7 YPA, 333 TD, 165 INT, 94.7 rating
Best year: (2004) 336 of 497, 67.6%, 4,557 yards, 9.2 YPA, 49 TD, 10 INT, 121.1 rating
Last year: 371 of 555, 66.8%, 4,002 yards, 7.2 YPA, 27 TD, 12 INT, 95.0 rating
The Cold, Hard Football Fact: Manning is second all time in career passer rating (94.7), behind only Steve Young (96.8).
The straight dope: Manning has put up such mountainous numbers that we get vertigo just looking up at them. You know the story: There's a very good chance – assuming he stays healthy – that he'll top the leaderboard in every major passing category in the history of the game. He's also never missed a game in an 11-year career,  proving to be one of the great NFL ironmen. And he makes funny commercials.
You know the other story, too: the knock on Manning has always been that he's not the same quarterback in the playoffs as he is in the regular season. And it's literally impossible to argue with that assessment. Manning's Colts are 117-59 (.665) in the regular season, which makes him one of the winningest quarterbacks in the history of the game. Yet Manning's Colts are a mere 7-8 (.467) in the postseason and have so many one-and-dones (a shocking six) that the organization should take out a patent on them. The Colts, for example, are 25-7 over the past two seasons – and failed to win a single playoff game.
Manning has also reserved the worst games of his career for the playoffs, dropping statistical clunkers in the 1999, 2002, 2003, 2004 and 2006 postseasons. His fans exhibit the same symptoms displayed by members of the Cult of Dan, crediting Manning for all of Indy's regular-season success and blaming everybody else for the team's poor postseason record. But even Indy fans, and factless Manning nut-scrubbers like Pete Prisco, can't explain away the dreadful 13.6 PPG the Colts have scored in their eight Manning Era playoff losses.
This failure to replicate his regular-season success in the postseason is the big difference between Manning and the top three quarterbacks in the game today.
The outlook for 2009: It's a year of huge changes in Indy. But one thing will remain constant: the Colts will be a regular-season force as long as Peyton is taking the snaps.
3. Kurt Warner
Type of Quarterback: Prolific Stat Monster/Modern Gunslinger hybrid
Career: 2,327 of 3,557, 65.4%, 28,591 yards, 8.0 YPA, 182 TD, 114 INT, 93.8 rating
Best year: (1999) 325 of 499, 65.1%, 4,353 yards, 8.7 YPA, 41 TD, 13 INT, 109.2 rating
Last year: 401 of 598, 67.1%, 4,583 yards, 7.7 YPA, 30 TD, 14 INT, 96.9 rating
The Cold, Hard Football Fact: In 86 combined seasons, the Rams and Cardinals organizations have appeared in just four Super Bowls -- three of them with Warner at the helm. His career average of 8.04 YPA is the best by any QB since 1960.
The straight dope: The Cold, Hard Football Facts caused a bit of a national flap here and on when we declared Warner better than Peyton Manning. But we stand by the argument and only someone blinded by hype or  handicapped by the scourge of Spinal Manningitis would disagree. Warner in his bizarre career has reinvigorated not one but two different moribund franchises. In fact, the one that dumped him back in 2003 has never really recovered from the mistake and can only wish that it got a mulligan on personnel moves.
The Cardinals, meanwhile, won more playoff games last year with Warner (three) than they had won in their previous 88 seasons of pro football history (two), before finally falling in the Super Bowl to what was a superior Steelers team by most any measure.
Along the way, Warner put up some of the most explosive numbers in the history of the game. He stands among the very best in the history of the game in all of the most important passing indicators, including YPA (fourth all time), passer rating (third) and completion percentage (second). In fact, his career average of 8.04 YPA is the best by any quarterback of the past half-century.
He's also proven that he can get it done in the playoffs: among active quarterbacks, only Tom Brady has played in more Super Bowls (4 vs. 3) and his postseason record of 8-3 is third among active quarterbacks.
But the gunslinger side of Warner has also got the best of him. In two of his three Super Bowl appearances (against the Patriots and Steelers), his critical INT that was returned for a TD proved the difference between victory and defeat (as it always does in the Super Bowl). His career TD-INT ratio (1.60 TDs for every INT), which is subpar by today's standards, is the evidence of the gunslinger within him. It's the most obvious flaw in an otherwise highly polished game that has produced historic results for two different organizations.
The outlook for 2009: WR Anquan Boldin is pissing and moaning, while offensive coordinator Todd Haley left to take the head job in Kansas City. But Warner is fresh off one of the best seasons of his career and perhaps the best performances ever by a 37-year-old QB. If the Cardinals can shore up one of the worst pass defenses in football (it allowed 36 TD passes last year, easily the most in the league) then they can make another run in 2009. In either case, Warner gives the team, at the very least, a Super Bowl-caliber offense and a proven big-game gunslinger.
2. Ben Roethlisberger
Type of Quarterback: Clutch Playmaker
Career: 1,189 of 1,905, 62.4%, 14,974 yards, 7.9 YPA, 101 TD, 69 INT, 89.4 passer rating
Best year: (2005) 168 of 268, 62.7%, 2,385 yards, 8.9 YPA, 17 TD, 9 INT, 98.6 passer rating
Last year: 281 of 469, 59.5%, 3,301 yards, 7.0 YPA, 17 TD, 15 INT, 80.1 passer rating
The Cold, Hard Football Fact: Big Ben's career average of 7.86 YPA is the third best in modern NFL history (since 1960).
The straight dope: The knock on Big Ben has always been that he's been lucky to play with a great defensive club with a great commitment to the run on offense. However, teams don't consistently win games, and don't consistently win Super Bowls, without clutch play at quarterback -- no matter how good they are defensively or no matter how often they run the football. And, with the possible exception of No. 1 on our list, no quarterback in football today consistently produces clutch plays in key moments more often than Roethlisberger.
The 2008 season was textbook Big Ben: hamstrung by one of the worst offensive lines in the league (28th on our Offensive Hog Index), Roethlisberger had a subpar statistical season. But with everything on the line – and in the last thing we all saw at the end of the 2008 football season – Roethlisberger led his Steelers on one of the great drives in Super Bowl history, ending it with a gorgeous, clutch pass to Santonio Holmes for the game-winning touchdown. (We ranked that drive the third best in Super Bowl history earlier this year.)
However, if you're looking for a telling stat that underscores Big Ben's success – the underlying stats are always there if you trust in the Cold, Hard Football Facts – look no further than Big Ben's 7.86 YPA, the sixth best mark in the history of the NFL. In modern times, only Warner (8.04 YPA) and Steve Young (7.98 YPA) were more effective at getting the ball down field.
Other quarterbacks put up bigger, better numbers. But the bottom line is that no fandom outside of New England can rest more comfortably knowing that they have a quarterback who can make plays and pull out victories in the most critical games and moments of the season.
The outlook for 2009: Big Ben & Co. find themselves playing for "team of the decade" status. With another title this year, they'll have won three Super Bowls in the second half of the decade, after the Patriots won three in the first half of the decade. Clutch quarterbacks revel in these moments.
1. Tom Brady
Type of Quarterback: Steam Shovel of Efficiency
Career: 2,301 of 3,653, 63.0%, 26,446 yards, 7.2 YPA, 197 TD, 86 INT, 92.9 passer rating
Best year: (2007) 398 of 578, 68.9%, 4,806 yards, 8.3 YPA, 50 TD, 8 INT, 117.2 passer rating
Last year: 7 of 11, 63.5% 76 yards, 0 TD, 0 INT, 83.9 passer rating
The Cold, Hard Football Fact: Tom Brady's 2.3-to-1 ratio of TDs to INTs is the best in pro football history. His regular-season (87-24) and postseason (14-3) records as a starter are each the best among active quarterbacks.
The straight dope: Some bloom has come off the Brady rose over the past couple seasons. His brilliant, record-setting 2007 campaign ended with one of the great offensive clunkers in the history of the game in Super Bowl XLII, and last year his season was over a few minutes after it started. But even if he never takes another snap, his rise from unknown back-up to elite, championship-winning statistical juggernaut has been the singular storyline of the first decade of the 21st century.
He's won all the hardware imaginable, and his career 92.9 passer rating is fourth all time, and best among any cold-weather quarterback. We can only imagine what his numbers might look like had he the benefit of playing in a stat-ballooning dome or anywhere but arguably the worst-weather arena in the game.
His return from injury, meanwhile, will be the singular storyline of the 2009 season. No player in the game today is a bigger difference maker in the eyes of pro football observers or oddsmakers, or in the irrefutable findings of the Cold, Hard Football Facts.
His 2007 season was arguably the most explosive in the history of the game. But Brady's greatest attributes are his efficiency, his care with the ball and his remarkable consistency. The greatest part of his 50-TD season, for example, was that he threw just 8 INTs, despite slinging the ball all over the field game after game. His rate of 2.3 TDs for every INT is unmatched by any quarterback. And even when he doesn't light the world on fire every game or every week, the duds are fewer and farther between than they are with any other QB in the game today. That consistency at quarterback over the past decade is the single biggest reason why the Patriots have been the most consistent winners in football over the past decade.
The outlook for 2009: If the Patriots find a way to improve their dreadful pass defense, the return of Brady makes them obvious favorites to win their fourth Super Bowl of the decade.