It's now or never for Earnhardt Jr. in the Chase's most arresting race

Heading into Talladega Superspeedway, three drivers have emerged as title favorites with six races left in the playoffs: Brad Keselowski (the current leader in the standings), Jimmie Johnson (five points back) and Denny Hamlin (16 points back).

But the best chance for the rest of the playoff field to narrow the gap on this trio this season will take place at Talladega, which is NASCAR's biggest, fastest, scariest track. As I wrote in the magazine this week, Talladega is the most arresting -- and important -- race of the Chase for one reason: The Big One.

Because of the restrictor plates that are placed on the carburetors at Talladega, which reduce the airflow into the engines and limit the top speeds to 200 mph, the cars travel in a tight pack around the 2.66-mile tri-oval. The slightest driver mistake can trigger a massive, multi-car wreck that can take out as much as half of the 43-car field in a matter of a few heartbeats. If a driver can navigate through this mass of spinning, smoking cars, then his title hopes will remain alive; if he can't, then his season may very well implode.

It's happened before. In 2008 Carl Edwards arrived at Talladega trailing Jimmie Johnson by 10 points in the standings. But then The Big One erupted in front of Edwards and he ended up crumpled against the wall. Johnson, though, was able to nimbly avoid the accident, and he left 'Dega with a 72-point lead over Edwards. Just like that, Johnson was able to cruise to the championship without really having to check his rear view mirror for the rest of the playoffs.

So at some point on Sunday, The Big One will strike. Who it hits -- and whom it doesn't -- will go a long way toward determining your 2012 Sprint Cup champion.

Here are the four drivers to watch once the green flag flies on 'Dega:

1. Brad Keselowski

Keselowski had the race of his life at Talladega in April 2009. In only his fifth start in the Cup series, he held his ground on the low-line as he and Carl Edwards charged to the finish line, nose-to-nose. Edwards tried to move Keselowski up the track, but Keselowski didn't budge, which caused Edwards to go airborne and fly into the catch-fence in one of the most spectacular -- and scary -- crashes in the last decade in NASCAR. (Neither driver was hurt; a few fans suffered injuries.)

Keselowski won the race. and afterward, in the media center, he essentially said that wasn't going to back down to anyone, ever, at any time. As I sat listening to Keselowski that afternoon, I remember thinking, This rookie, with this attitude, is going to contend for the championship one day. Well, that day has now arrived.

It's important for Keselowski to have a strong finish on Sunday, because -- on paper, at least, based on average finishes -- it appears that he'll be at a decided disadvantage to Johnson and Hamlin at the final six tracks. Keselowski won at Talladega in the spring; if he can duplicate that effort on Sunday, it will send the message throughout the garage that he'll be a title threat all the way to the season finale at Homestead.

2. Jimmie Johnson

Johnson has one goal on Sunday: survive.

Talladega, by far, is his worst track of the 10 in the Chase. Yes, he does have two career victories at the high-banked tri-oval, but his average finish in 21 starts is only 17.7 and he hasn't come in higher than 26th in his last two Talladega races. What's more, Johnson has yet to even finish a restrictor-plate race this season. He crashed in both Daytona events and blew an engine in the spring at 'Dega.

So all Johnson wants to do is avoid The Big One. I expect him to drop to the rear of the field early with teammate Dale Earnhardt Jr., cruise along for the majority of the race out of harm's way, then make his move with about 30 laps to go and try to maneuver to the front. Using a similar strategy, Earnhardt pushed Johnson to victory here in April of last year.

3. Denny Hamlin

After Hamlin's performance last weekend at Dover, you have to like his title chances. To review: at Dover, which by far was Hamlin's worst track in the Chase, he won the pole, led 39 laps and finished eighth. Considering he hadn't finished higher than 16th in his previous three Dover starts, this was a moral victory for the No. 11 team.

Because Hamlin has done so well at the six final tracks in the Chase, his objective on Sunday is the same as Johnson's: keep his fenders clean and simply leave with a top 10 finish. If he can do that, he should be a factor in the title hunt all the way to the final laps at Homestead.

4. Dale Earnhardt Jr.

There's only one way to describe Earnhardt's first three races in the Chase: disappointing. After tying Jimmie Johnson for most top-10 finishes in the regular season (17), Earnhardt finished outside the top 10 in back-to-back weeks (13th in New Hampshire and 11th at Dover). So now he heads to Talladega seventh in the standings and 39 points behind Keselowski.

This means it's officially now-or-never time for Earnhardt, which is arguably his best track in the Chase. Back in the early 2000s, he either finished first or second at Talladega over seven consecutive races (and he won five of them). Earnhardt remains one of the top plate racers in NASCAR today, able to ride the draft as effortlessly as his late father, who once claimed -- with a wry smile -- that he could see the air as it flew over his car.

Alabama has always been Earnhardt country, and on Sunday look for a return of the Earnhardt magic. With Johnson pushing Junior in the closing laps, it says here that Earnhardt will win his first race in the Chase -- and suddenly become a serious player in the playoffs with six races left.