"It's pretty much unquestioned that quarterback is the most important position in any team sport. "
Oh, Tim.... In the middle of that otherwise excellent article about quarterbacking, you dropped a plonker.
I grant that a great QB can elevate teams that have no business winning, and bad ones can sink their teams at inopportune times. But if you look at the timing and intricacies involved in a typical pro offense - as well as the intricacies facing them in the typical pro defense - then you'd have to conclude that there's a lot out of the quarterback's control. Without an offensive line to block or a credible running game, even terrific quarterbacks can look mortal. Elway didn't win* until he had Terrell Davis and the chip-blocking, borderline-kneecapping offensive line to support him. Marino never won. Neither did Jim Kelly nor Fran Tarkenton, in four tries each. Even if everything works perfectly for the offense and the QB, a team can lose a lot of 41-37 games if their defense is unequal to keeping the other team's attack under control.
* By "win" I mean the NFL title; obviously these are successful quarterbacks, one and all.
Besides, there's a long list of pedestrian (or worse) signal callers with Super Bowl visits: Morrall, Lamonica, Morton, Grogan, Grossman, Humphries, Chandler, Collins, O'Donnell... and possibly Hasselbeck and Delhomme (jury's out on them so far). Some have gone on to win: Trent Dilfer, Brad Johnson, Mark Rypien, Ken Stabler, Jim McMahon, and Eli Manning (until proven otherwise). Important, clearly: but there are too many other important factors to make this the sine qua non of individuals in team sports.
I'd argue more for a possibility that Keown didn't even consider - the hockey goaltender. Admittedly, my bias as a goaltender is in play here, but the primary reason I love being a keeper is precisely this. The game always goes through me. If I'm bad, then we're most likely done. If I'm great, then my team, no matter how lousy, has a chance. We only need one fluke shot to ping off a defenseman to have that chance, as long as I'm at my best. Recently I saw a game where the shots were 60-11 (no joke) and it still went into a shootout; the goalies were the leveler. One guy was a little soft, and the other was lights out.
Sure, the goalie has no control over the offense. He can't possibly win if nobody scores a goal. In fact, the goalie and the baseball pitcher (at least the AL version) are alone in that distinction - they can never win the game alone. But if they do their job perfectly, then the least mistake by the other side will win the game for them. On the other hand, if a QB does his job perfectly, his team can still lose. He needs somebody to catch those pretty passes, and give him time to stay upright to throw them, and a kicker to turn near misses into three points, and a whole team of guys to keep the other team from scoring.
That brings up what I think is the biggest argument for the goalkeeper as the most key individual in a team sport - the mistake factor. A QB can make a ton of mistakes that wind up, ultimately, not hurting his team. He can bounce passes off defenders' chests and hands, or fumble, or get sacked, and still not turn over the ball. His team can score despite him, or simplify their offense to get more out of him, or take the game out of his hands as much as possible. Likewise, a basketball player can miss tons of shots but his team can rebound those misses; a pitcher can walk a bunch of guys and still squirm out of it, or groove a fastball that gets fouled away or smoked right at a fielder. A forward can miss a wide-open net, or a defender can give up a breakaway... but those mistakes do not automatically lead to goals against. None of the other mistakes are directly harmful in the way that a goalie's mistakes are. If the keeper screws up, then it's likely going into his net, and that's that. And if it's a soft goal it not only hurts immediately on the scoreboard, it usually dampens his team's performance. Nothing is worse than five minutes of domination without result, followed by a weak counterattack that leaves you down a goal.
Bottom line is, if the goalie is perfect, his team can never lose the game. You can't say that about a quarterback, so I'd give the edge to the keepers.
And that being said - I agree with the other 90-ish percent of the column, as usual. If you do need a quarterback, draft one before you need him, not the moment you do. Learn from the unfortunate fates of Alex Smith, Joey Harrington, Rick Mirer, Akili Smith, Andre Ware, Browning Nagle, Ryan Leaf, etc. etc. Much shorter than any QB list above is the list of rookies who made immediate Super Bowl visits, much less won them. The difference between rushing and ruining a guy vs. seasoning and succeeding with him is the difference between Steve Walsh and Steve Young.