What a difference a year makes.(NASCAR)

In the cruel world of professional sports, athletes can rise and fall faster than Ryan Newman can take a hot lap around Bristol Motor Speedway. But the plunge of several of last year's Chase-contending teams and drivers is disturbing.

Take Newman, for instance. After 11 races last year, his No. 12 team was seventh in points, and it finished the season sixth. Now he's 19th with the same team.

Kurt Busch, Newman's new Penske teammate, is another example. Busch was sitting solidly in fifth after 11 races last year, and Newman's former teammate Rusty Wallace was 12th. Today, Busch is driving the retired Wallace's No. 2 car and has dropped to 18th in the standings.

The problems at Penske are puzzling. The organization wasted too much time rebuilding the Intrepid rather than forging ahead with the Charger. Busch certainly didn't sign up for the mess he inherited with the No. 2 crew. All but two team members have been replaced since Wallace's departure.

The team Busch defected from--the No. 97, which is now the No. 26--also is struggling with Jamie McMurray. McMurray was ninth in points at this time one year ago, which was impressive considering the turmoil on his Chip Ganassi Racing team at the time.

Now driving for Roush Racing, McMurray is backed by a title-contending squad. Still, the No. 26 was 21st in points after seven races, so Roush Racing made changes. Longtime crew chief Jimmy Fennig was bumped to the Busch program, and Roush moved Carl Edwards' crew chief, Bob Osborne, over to guide Mac in what can only be a sink-or-swim move. If Mac can't get up to speed with Osborne, he'll need a better excuse than "it's the cars."

The biggest fall has been by Jeremy Mayfield, who was 16th in points going into race No. 12, the Coca-Cola 600, in 2005 but eased his way into the playoffs for the second consecutive season. And though he was a no-show in the the Chase last season, there's no excuse for Mayfield dropping to 34th in points this year, especially when Evernham Motorsports teammate Kasey Kahne is on such a phenomenal run with what was last season's No. 19 crew.