Championship on the line for Carl Edwards at Martinsville Speedway

With four races left in the 2011 Sprint Cup season, all eyes will be on one driver at Martinsville (Va.) Speedway on Sunday afternoon, the one driver that has sped to the front of the pack, the one driver that is poised to end Jimmie Johnson's five-year reign as NASCAR's champion. Yes, forget the other 42 men in the field at Martinsville, because this race is all about Carl Edwards.

Edwards appears tantalizingly close to his first Cup title. He holds a 14-point lead in the standings over his Roush-Fenway teammate Matt Kenseth -- which basically is the equivalent of 14 positions on the track -- and Edwards has been dominant recently at the final three venues on the Chase schedule. Consider: At Texas (site of Chase race No. 8, Nov. 6) Edwards has three wins in 13 career starts; at Phoenix (Chase race No. 9, Nov. 13) Edwards is the defending race winner; and at Homestead-Miami (Chase race No. 10, Nov. 20) Edwards is the defending race winner and has a career average finish of 5.7, which, statistically, makes Homestead his best track on the circuit.

Edwards' only weak spot left in the Chase is Martinsville, making this the last, best shot for rival drivers to make up ground on the points leader. In 14 starts at Martinsville, which is the shortest track (a .526-mile oval) on the schedule, Edwards' average finish is only 16.9 and he's notched just one top-five run. Edwards has always flourished on fast intermediate-length tracks like Texas and Homestead -- "They just fit my driving style," he says -- and usually struggled at slower, shorter places like Martinsville.

Edwards won't say this, but he'd be thrilled with merely a top-15 performance on Sunday.He knows if he can just be good at Martinsville, he'll be in a great position to hoist the big trophy in three weeks. So expect Edwards to be especially careful and cautious for most of the afternoon, knowing that a title is very much on the line.

Here are four other drivers I'll be watching when the green flag waves in the hills of Central Virginia:

1. Matt Kenseth

Edwards said this week that he's very worried about Kenseth making a hard charge over these final four races, and that concern appears warranted. Like Edwards, Kenseth's specialty is the 1.5-mile tracks. Also like Edwards, Kenseth rarely shines at Martinsville, where in 23 career starts he has zero wins and an average finish of 15.8.

Earlier this season, though, Kenseth did author a sixth-place run at Martinsville. If he can duplicate that on Sunday, he could close the points gap on Edwards. And if there's one driver right now who appears capable of running wheel to wheel with Edwards over the final three events, it's Kenseth.

2. Brad Keselowski

Keselowski remains the wild card in the Chase. He's third in the standings, 18 points behind Edwards. He keeps salvaging excellent finishes with seemingly average cars -- he came in fourth at Talladega last Sunday -- and remains within striking distance of pulling off what would be, frankly, one of the most improbable championships in the history of NASCAR.

In three career starts at Martinsville, Keselowski has one top-10 run and an average finish of 13.7. But statistics have meant little to the No. 2 team this season, as Keselowski has shown eye-popping improvement whenever the circuit has visited a track for the second time.

3. Tony Stewart

Stewart started the Chase with impressive speed (he won the first two playoff races), then slowed for two races (he came in 25th at Dover and 15th at Kansas), and now is on a nice little roll (eighth at Charlotte; seventh at Talladega). Only 19 points behind Edwards, Stewart still has an outside shot at capturing his third Cup title.

Stewart has not enjoyed his past few trips to Martinsville, where in his last three starts he hasn't finished higher than 24th. But Stewart has a knack for turning it on when it matters most, and I think he'll contend for the win on Sunday.

4. Jimmie Johnson

This just in: Johnson won't win his sixth straight title this season. After a disappointing 26th-place finish at Talladega, he's now 50 points behind Edwards. Even Johnson seemed to acknowledge that his days as the reigning champ were numbered when he noted after 'Dega that he was just going to try to finish as "high" in the standings as possible. You haven't heard that kind of diminished expectation from Johnson in a very, very long time.

But I think he'll be the man to beat this weekend. He's won four of the last 10 races at Martinsville, and it says here he'll get another W on Sunday. It will be too little, too late for the No. 48 team, but it will serve as a reminder that what Johnson and Co. have accomplished over the last five years is as impressive as anything in sports this century.