Darrell Green's ability -- and nothing else -- is the reason he's still effective at age 40.

Ever seen the movie North Dallas Forty? In the final scene, Nick Nolte's character, Phil Elliott, is cut from the team. His coach tells him, "Phil, you have a lot of ability, but there's more to this game than ability." It's perhaps the most telling statement about professional football. Whether it be a personality conflict with a coach, the salary cap, or seniority, there are so many superfluous factors that determine the length of an NFL player's career.

That's why, for me, the Olympics will be a nice change of pace. Track is the total antithesis of football -- it's beautiful in its simplicity. The first one from point A to point B wins. Victory isn't decided by an official's bad call or a stupid rule change. And the longevity of your career doesn't hinge on the whim of some coach who decides you're too old to compete. If you have the skills, you rule. Period.

Take Merlene Ottey. She is a Jamaican sprinter competing in her sixth Olympics. She is a chocolate-skinned beauty with dark, sullen eyes and seven Olympic medals (two silver, five bronze). She is equal parts elegance and explosive power -- everything I love about track and field. And she is 40 years old. At last week's Gold Coast Meet (a Sydney tuneup), she blazed a 10.91 in the 100 meters.

If Ottey played a team sport for money, she probably would have been cut long ago. She'd be considered too old, or too expensive.

Football does have one shining exception to this unfortunate reality -- Redskins cornerback Darrell Green. He's also 40. After 17 years in the league, Green can still throw a blanket on any receiver. Ask the Lions. Last Sunday they threw, repeatedly, at the new starting right corner. Deion Sanders.

I played with Green in 1994. Six years ago. I'm telling you, he's still the same guy with the same speed and the same skills. Give Daniel Snyder credit for recognizing that.

So in the next two weeks, check out Merlene Ottey burning up the track in Sydney and Darrell Green putting the shackles on the Cowboys and the Giants. Some coaches still say there is more to sports than ability, but I say that's just a whimper from the weak-minded.

Alan Grant covers the NFL (like a blanket) for ESPN The Magazine.