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Nextel Cup points leader Jimmie Johnson has been red hot in the second half of the Chase, but with one race to go in the playoff he knows misfortune could end his title chances, writes Allen Bestwick of MSNBC.com.

Denny Hamlin
Here’s my take on the key to Hamlin's chances on Sunday: Will he and his team have a clean race?

The young Virginian, who is the only rookie to have ever made the Chase, has really impressed me with his effort this season, and with the manner in which he’s handled competing for a championship.

His performances on the 1.5-mile tracks have been solid, but a couple of his results haven’t. At Kansas Hamlin was tagged for a pit-road speeding penalty which dropped him to 21st, and then he had a spin which dropped him to 25th.

He recovered to 14th only to make an extra pit stop for a wheel not completely tightened on a previous stop. His 18th-place finish after all that shows how strong a car he really had.

At Charlotte a 22nd-place starting spot put Hamlin in the wrong place as he was swept into a Lap-2 crash. After lengthy repairs in the garage, Hamlin returned to finish 28th -- 69 laps behind the winner.

At Atlanta Hamlin rallied back from a lap down to finish eighth, and backed that up with a sixth-place run at Texas.

If Johnson has trouble, Hamlin has had the speed to pull off the title, but will it be a clean day for the rookie? And will he be able to get past Kenseth and Harvick?

Dale Earnhardt Jr.
Here’s the driver that really intrigues me if Johnson has trouble. No championship contender except Johnson has been better on the 1.5-mile tracks during the Chase than Junior.

He’s finished in the top 10 at all four 1.5-mile tracks in the playoff -- 10th at Kansas, fourth at Charlotte, third at Atlanta, and sixth at Texas.

Junior is 52 points behind second-place Kenseth entering the finale. That means if Johnson has big trouble and Junior wins the race and gets maximum bonus points, Kenseth would have to finish 10th or worse, and Harvick and Hamlin fourth or worse for Junior to win the title.