When Peyton Manning or Rex Grossman steps under center to take the first snap in Sunday’s Super Bowl, where will your eyes be fixed? If you’re like most spectators, you’ll focus on the ball. But if you are a coach, former player, or football junkie, you’ll hardly ever follow the ball. You are too busy looking at zone-blocking schemes, pulling guards, defensive sets, stunting and blitz packages and cornerback-receiver match-ups to have time for the ball. Once you understand all that is going on, football is a much more complex sport than you ever knew when you were just a “ball watcher.”

I see a lot of ball watchers analyzing the presidential nominations contests these days. The balls are Sens. John McCain (R-Ariz.) and Hillary Rodham Clinton (D-N.Y.). Most beat writers and columnists can’t seem to follow too closely the staff and scheduling moves of these two frontrunners. But when the post-2008 election books are written, can we be sure that the saga will be the recounting a McCain-Clinton finale? The odds are that at least one of these two will falter. Just look at how often in past cycles an early frontrunner has fallen.

Here again, football gives us some perspective. At the beginning of this NFL season some top, sophisticated prognosticators predicted the Pittsburgh Steelers or Denver Broncos were sure title contenders. Neither team even made it to the playoffs.

Meanwhile, almost no ordinary Joes outside of Chicagoland picked the Chicago Bears before the season to be in the Super Bowl, much less to win it. While the Bears improved from a losing season in 2004 to an 11-5 winning record in 2005, few hoped for better in ’06. The club is well below the NFL’s salary cap because the roster is loaded with no-name players. And who would have guessed that a team with so little offensive experience, led by an injury-prone 26-year-old quarterback, would be able to get to the big game?

But some smart oddsmakers said that Chicago was set for a run like this. Yes, the Colts, led by an All-Pro quarterback and brimming with talent that’s bumping up against the salary cap, were 7-to-5 favorites to win the Super Bowl during the pre-season. But some in Vegas correctly saw the Bears as an improving team with a smart head coach. And most importantly, they have a solid defense, the kind of crew that insiders know wins championships. Bookies set the pre-season chances of the Bears winning it all at a hopeful 22-to-1.

Today, one Vegas site (BetUS.com) has Hillary Clinton as the frontrunner with 5-to-4 odds of winning the presidency, while John McCain is close by with 3/1. While some of this site’s numbers are silly (Al Gore at 8/1 or ex-Virginia Republican Sen. George Allen at 7/1), others are provocative. For example, Mark Warner at 7/1, Rudy Giuliani at 8/1, and Jeb Bush and Mike Huckabee, both at 20/1, places all four of them closer to the top prize than anyone suspected the Bears would be when the season began.

The possibility that a “second-tier” candidate could leap over the front-runners is not the only reason to look harder at the underdogs. Even candidates like Kansas Sen. Sam Brownback (R) who now attract only single-digit numbers in pre-primary polls have an effect on the overall chemistry of the field. New candidates take donors, activists, staff and consultants away from the front-running candidates. Even if these resources don’t allow the second- or third-tier candidate to go to the head of the field, they may influence the overall balance of power and allow a second- or third-place candidate to move into the driver’s seat.

So quit looking at the frontrunners for a moment to see the whole field of contenders. It’s going to be a long, interesting game.

Hill is director of Hill Research Consultants, a Texas-based firm that has polled for GOP candidates and causes since 1988.