The great ones rarely go out on top.
For every John Elway, walking off into the sunset with Super Bowl MVP honors in his final game and with a pair of championships in his last two seasons, there are the shadows of legends like Joe Namath, hobbling to an inglorious four-INT end with the Rams before being replaced by a young Pat Haden; or the great Johnny Unitas, misfiring in a final few pathetic appearances with the Chargers before ceding the floor to rookie Dan Fouts.
For every Jerome Bettis, returning to his hometown of Detroit to win a Super Bowl in his last football game, there is a hard-headed Jim Taylor, returning to his native Louisiana, only to get that same cranium pounded into a soft  mush in his futile effort to carry the ball for the lousy expansion Saints; or a once brilliant Shaun Alexander, waiting for a phone that never rings, despite his youth and despite the fact he was the most dominant player in football just a few short years earlier.
And, of course, for every Jim Brown who calls it quits at the very peak of his powers, forever remembered as a superhuman force of nature, beloved in his one NFL whistle-stop, there are the BrettFavres (or even Drew Bledsoes), who linger on as mercenaries and hired guns who can't let go, sullying the images of the glory days back in the far-flung cities that once embraced them like native sons.
Finally, then, there is Kurt Warner, who retired Friday after a prolific, tumultous and unusual career.
He certainly dabbled in sports stereotypes: the overlooked Natural who comes out of a proverbial pigskin Podunk to confound the so-called experts with rare skills; or the aged phoenix who revives his career in his later years and in a new town, when everyone thought it was over.
Some players take the stage with a chance to act out one of those archetypes: Tom Brady and Unitas starred in the former role; Jim Plunkett and George Blanda starred in the latter role (cap-tip to Al Davis), as did Earl Morrall, not once but twice (cap-tip to Don Shula).
Warner played both parts, and performed remarkably well in each role. Which is why, ultimately, Warner's is a unique story – unique in the very sense of the word, too: that is, one of a kind, unprecedented; not unique in the casual way we so often toss around the word to describe something rare, compelling or merely interesting.
We don't need to rehash the Warner story. If you're the type of person who spends precious moments on earth visiting sites like this one, you are certainly familiar with the Warner tale.
But it's the uniqueness of the story – the highest highs and the lowest lows – that makes the big question about his career so compelling in the wake of his retirement:
Is Kurt Warner a Hall of Famer?
There are arguments on both sides.
On one end is the unprecedented nature of Warner's inexplicable rise to NFL MVP, his sudden fall at what seemed the height of his powers, and then the resurrection in the deepest, darkest waterless back-country of the NFL.
On one end are the unprecedented heights to which he carried not one but two acrophobic pro football franchises, tempered by several years in between searching for success while battling younger but less productive guns for a starting job (Marc Bulger, Eli Manning, Matt Leinart).
On one end are the gaudy, history-making stats in the regular season, in the playoffs and in Super Bowls, tempered by two colossal mistakes that proved the difference between a guy who now wears one Super Bowl ring, instead of a guy who struts around with three. (Warner threw pick-sixes against the Patriots in SB XXXVI, a three-point loss, and against the Steelers in SB XLIII, a four-point loss.)
Each of these paradoxes make for a unique run through history and fails to give us a straightly drawn parallel with which to compare Warner to other quarterbacks. It's these paradoxes that will make the Hall of Fame question linger over the football world for at least the next five years, and maybe longer.
For our part, we've gone down the check list and the answer is obvious: the answer is yes. Warner is in fact a Hall of Fame quarterback. Here's why.
Three Super Bowl appearances
Hall of Fame voters put a lot of stock in Super Bowl appearances. And three is the magic number. Warner, of course, played in three Super Bowls – two with the Rams, one with the Cardinals.
Sure, he lost two of those three games.
But every other quarterback who's started at least three Super Bowls is in the Hall of Fame, including those who never won (Jim Kelly, Frank Tarkenton) and those who put up rather ordinary numbers in their regular-season careers but later found success in the Super Bowl (John Elway, Troy Aikman, Terry Bradshaw, Bob Griese).
Two Super Bowl appearances remains a wildcard in the eyes of Hall of Fame voters: Craig Morton started two Super Bowls for two different teams (1970 Cowboys, 1977 Broncos). He played poorly both times and he'll never make it into Canton (nor should he). Joe Theismann led the Redskins to consecutive Super Bowls in 1982 and 1983. He won one and lost one. He's not going to Canton, either (nor should he).
Jim Plunkett led the Raiders to two Super Bowls (1980 and 1983), played very well in both and won both. Yet he's not in Canton, either, and it looks like he'll probably never get there (though his Hall of Fame merits make for an interesting debate, too).
At the other end of the spectrum, plenty of two-timers are in the Hall of Fame or destined for it: Len Dawson, Bart Starr, Brett Favre, Peyton Manning and (probably) Ben Roethlisberger.
In either case, two Super Bowl starts is a Hall of Fame question mark. Three Super Bowl starts is a Hall of Fame exclamation point. Warner started three Super Bowls. You do the math.
Gaudy numbers
Nothing excites fans and Hall of Fame voters quite like gaudy passing stats.
Big passing numbers are the reason why borderline Hall of Famers with little postseason success (Dan Fouts, Warren Moon) boast bronze busts in Canton, while many of the game's greatest defenders – guys with no gaudy stats for voters to digest – are wondering why the caller ID never displays a 330 area code. (Yes, we're talking about you, Ken Riley, fifth on the all-time INT list; and you, too, Robert Brazile, a seven-time Pro Bowler and member of the 1970s All-Decade Team).
Warner's stats stand among the best of them. His career passer rating of 93.7 is the fifth best in history, a shade ahead of Tom Brady (93.3) and Joe Montana (92.3). Montana was fast-tracked to Canton; Brady will be, too.  Warner's career average of 7.95 yards per attempt is among the 10 best marks in history. In other words, when Warner stepped back to pass, the results were among the most productive of any quarterback who's ever played the game.
Warner passed for 4,830 yards in 2001 – the third most prolific season in NFL history, behind only Dan Marino in 1984 (5,084) and Drew Brees in 2008 (5,069).
He carried his gaudy numbers into the playoffs and onto the sport's biggest stage. Warner owns not one, not two but the three most prolific passing days in Super Bowl history: 414 yards vs. the Titans in Super Bowl XXXIV; 377 yards vs. the Steelers in Super Bowl XLIII; and 365 yards vs. the Patriots in Super Bowl XXXVI. If you admire statistical anomalies, the three most prolific passing days from one guy, amid 86 opportunities to compete for that particular crown, leaps off the scorecards. Warner's combined 1,156 passing yards are the most in Super Bowl history.
If you need a few other morsels to munch on, Warner is the only quarterback to toss five touchdowns twice in the playoffs, and he came out on the winning end of two of the three highest-scoring shootouts in postseason history: his Cardinals outlasted the Packers, 51-45, earlier this year; his Rams outscored the Vikings, 49-37, during their championship season of 1999. It was Warner's first postseason game.
Two league MVP awards
Warner earned league MVP honors in both 1999 and 2001. The list of two-time MVP winners is a short one and all are in the Hall of Fame or destined for it: Johnny Unitas, Joe Montana, Steve Young, Brett Favre, Peyton Manning.
Warner deserves Hall of Fame consideration for that reason alone: twice in his career, not matter how rocky it was, he was the best and most valuable player in the NFL.
The greatest debut season ever
Warner was, for all practical intents and purposes, a 28-year-old rookie when he unexpectedly took over the starting gig with St. Louis in 1999.
His entire paid career before kickoff of the 1999 season had consisted of a few seasons in the second-rate semi-pro sideshows in Europe and the Arena League and 11 pass attempts in one NFL appearance with a lousy Rams team in 1998.
Yet he exploded onto the scene with one of the most productive passing season the NFL had ever seen. Most notably, Warner led the league with 41 touchdown passes – a mark that had been surpassed just twice at that point in pro football history, and both times by Dan Marino (48 in 1984; 44 in 1986).
He ended the season with league MVP honors, a game-winning touchdown pass in the Super Bowl and Super Bowl MVP honors.
It's difficult to envision a greater storybook season by any player, let alone by a guy nobody had ever heard of back in September.
The rarity of the career
Warner's career is, in our estimation, a unique one – that is, there's never been one like it. But even if you don't agree, nobody can refute that it was a rare career.
He accomplished so much with two different teams, under such unusual circumstances, and with such prolific numbers. Those factors alone should weigh heavily in the Hall of Fame debate.
Warner made history with two teams
The fact that not one but two franchises enjoyed some of the greatest seasons in their history is, to us, the Hall of Fame clincher for Warner.
The Rams were an NFL power back in the 1940s and 1950s, winning titles in 1945 and 1951 and playing for titles several other times. They had even enjoyed quite a bit of success – but no championships – in the 1970s and 1980s.
Yet they had gone nearly a half century since their last title, when the unknown Warner unexpectedly took over the team just before the start of the 1999 campaign. The Rams suddenly dominated the NFL, behind Warner's MVP effort.
They offense exploded with Warner at the helm, becoming the first and only team to score 500 points in three straight seasons. More importantly, an organization that had appeared in just one Super Bowl suddenly appeared in two under Warner; an organization that had never won a Super Bowl earned its only Super Bowl victory with Warner at the helm.
The turnaround he inspired in Arizona is probably even more impressive. The Cardinals were the worst franchise in North American sports, winning just two playoff games in their entire history – from 1920 right up through the 2008 season. A team that had won just two playoff games in 88 years doubled that total in two years with Warner the undisputed No. 1 quarterback.
Warner shared playing time in Arizona with Josh McCown in 2005 and with 2006 No. 1 draft pick Matt Leinart for two seasons before finally taking over the reigns in 2008 – he started all 16 games in an NFL season for the first time since his 2001 MVP season. The result was, yes, his first Super Bowl appearance since that 2001 season.
The 2008 Cardinals scored an average of 32 PPG as they won three postseason games – each against teams with better records – surpassing in three weeks the number of playoff wins the entire pathetic franchise had won in its first 88 season of NFL football.
Yes, the Cardinals ultimately lost that Super Bowl, falling 27-23 to Pittsburgh, its dominant defense and some last-minute heroics by Steelers quarterback Ben Roethlisberger.
And, yes, they Cardinals also lost because of a very bad decision by Warner: his interception deep inside Pittsburgh territory resulted in James Harrison's 100-yard touchdown, the longest play in Super Bowl history and one of two mistakes that cost Warner victories in two different Super Bowls.
But there are plenty of Hall of Fame quarterbacks who never came that close to winning it all: Warren Moon, Dan Fouts, Sonny Jurgensen, to name three passers who put up big numbers but never battled for a title.
There are plenty of Hall of Fame quarterbacks who broke records or played for titles with one franchise, but few who accomplished either feat with two: Norm Van Brocklin, Fran Tarkenton and Y.A. Tittle appear on the short list.
There are plenty of Hall of Fame quarterbacks who never produced the prolific seasons we've seen out of Warner: such as John Elway, Troy Aikman and Jim Kelly, to name three members of the modern pantheon of passers whose best numbers pale in comparison to Warner's best numbers.
In the end, there are no quarterbacks in history like Warner. And, for that reason alone, he someday deserves his bronze bust in Canton.