After entering the Chase third in the points, Jimmie Johnson has surged to a 72-point lead in the Cup playoff with six races to go. Stephen A. Arce/ASP Inc/Icon SMI

SI.com's Mark Beech offers the most intriguing news, notes and analysis fans need to know heading into each week's race.

Green flags

With six races left in the season, it's clear that the 2008 Cup championship is Jimmie Johnson's to lose. After his ninth-place run at Talladega last Sunday, he leads Carl Edwards by 72 points. Of the other 10 drivers in the Chase, only the surprising Greg Biffle, who trails Johnson by 77, retains a realistic chance of winning this year's title. This is a three-man race now.

The strange thing is that nobody inside the Cup garage finds the present circumstances surprising -- that after a season of domination by Edwards and Kyle Busch, Johnson has asserted himself as the one to beat. Perhaps we expected this because he's won the last two championships. Maybe the way he overtook Jeff Gordon in the Chase a year ago cemented his reputation as racing's greatest closer. And maybe, deep in our bones, we know that he's the best when the races count the most. We've seen his show, and it's been almost impossible to miss the message.

Looking ahead, it's hard to find a hole that Johnson could fall into. Not only does he have a history of success at Charlotte, but also at Martinsville (4 wins), Atlanta (3), Texas (1), Phoenix (2). Only at Homestead has he failed to reach Victory Lane, but with five top-10 finishes in seven starts, only a fool would try to claim he hasn't had success there.

Is there hope for Edwards? Certainly. He's been terrific on intermediate tracks this year, and if he can finish in the top five at Martinsville (where he has just one top-10 finish in eight starts), he should maintain a position within striking distance of the top spot. But make no mistake: he is climbing a mountain.

Johnson has been just as good on the intermediates in '08, and he's going to have to make a mistake -- or get caught up in somebody else's mistake -- to leave an opening that Edwards can drive through. Perhaps that's why Cousin Carl tried so desperately to pass Johnson on the final lap at Kansas two weeks ago -- a move that exposed the beads of sweat on his brow.

Edwards is right to sweat. For the third straight year, it seems, Cup fans are getting a look at racing's greatest finishing kick. Only disaster can stop Johnson now.

How to drive ...

Lowe's Motor Speedway

Kasey Kahne, who won at Charlotte last May, talks about why he likes racing at LMS: "It's a track where I seem to know what the car needs to go fast. The line that you need to run here is so crucial. Lowe's Motor Speedway is such a sensitive track, you can really mess up here by missing your line by just a little bit or not slowing down quite enough getting to the white line throughout the race. It's a great track and hopefully we can continue to keep up the success here and get a win."

Pit stops

5: Races that points leader Jimmie Johnson has won at Lowe's Motor Speedway

0: Times Johnson has started the second LMS race with the points lead

72: Points lead for Johnson over Carl Edwards

Charlotte memories

October 5, 1986: Dale Earnhardt leads 80 laps en route to victory in the Oakwood Homes 500 at Lowe's Motor Speedway. The win is his fourth of the season and helps propel the Intimidator to his second Cup title.