Jimmie Johnson could afford to gamble on gas in Sunday's Carfax 400, Mark Martin couldn't.

Though he hasn't clinched a spot in the Chase for the NASCAR Sprint Cup, Johnson was second in the standings entering the race at Michigan International Speedway and a virtual certainty to make his sixth straight Chase. Martin, on the other hand, came to Michigan eleventh in points. Though he has collected a series-best four victories this season, Martin is on the bubble when it comes to the Chase.

In practical terms, the only thing at stake for Johnson in Sunday's race was the bonus he would have collected for the victory. When the Chase is set at Richmond on 12 September, each driver in the field of twelve will have his points reset to 5000 plus ten for each win. As it stands now, Martin would start the Chase as the top seed with 5040 points, followed by Johnson - after three wins - at 5030. Kyle Busch, who also has three victories, is 15th in points and outside the Chase with three races left before the field is set.

For Martin, another ten-point bonus was small reward compared with the risk of running out of fuel and jeopardising his position in the Chase. Nevertheless, both he and Johnson gambled on fuel mileage - and both lost.

For Johnson, the consequences were cosmetic. Out of gas and forced to pit with two laps left, Johnson finished 33rd and lost second place in the standings to Jeff Gordon. But he remained comfortably eligible for NASCAR's post-season.

For Martin, however, the consequences were potentially devastating. His #5 Chevrolet ran out of fuel on the final lap, and Martin coasted across the finish line in 31st place. He lost a position in the standings, and - worse still - now leads 13th-place Brian Vickers, Sunday's race winner, by just twelve points.

Martin's crew chief, Alan Gustafson, fell on his sword after the race and took full responsibility for the risky call.

"This is completely on my shoulders today," Gustafson said, "There's no way to make it pretty. We had a great racecar and ran out of fuel. I made the call, and I knew as soon as I did it that I shouldn't have. We lost a lot of points, but I'm by no means giving up. We have great racecars, we're just going to have to have three great races."

Martin, however, now approaches those three races - at Bristol, Atlanta and Richmond - with no margin for error. Additionally, he has two drivers chasing him, Vickers and Clint Bowyer, who have made dramatic moves in the standings in recent weeks. Bowyer finished eighth Sunday, climbed to 14th in the standings and trails Martin by 58 points.

As Martin knows full well, anything can happen on the high banks at Bristol. In March, Martin won the pole and finished sixth in his first start at the concrete half-mile since 2006, but in his twelve previous races there, he posted one top ten.

What Martin has accomplished this season, his first full-time competition since 2006, is remarkable. He has won as many races as his three Hendrick Motorsports team-mates - Johnson, Gordon and Dale Earnhardt Jr - combined, but the devil is in the details. In retrospect, for safety's sake, Gustafson should have brought Martin to the pits under caution on lap 159, when Earnhardt stopped. Instead, Martin had to try to nurse 102 miles out of his fuel cell after stopping with Johnson on lap 149. Earnhardt went on to finish third.

The Hendrick teams do almost everything well, but winning fuel-mileage races is not their forte.

"We've won one race on fuel mileage - ever - and it's just not what we're good at," Johnson said of his own team after the race.

In a magical year for Martin, there has been talk of a championship for the 50-year-old driver, who has finished second in the standings four times. In order to win the title, however, you have to make the Chase, and the ill-advised gamble on Sunday has put Martin in jeopardy.

by Reid Spencer / Sporting News NASCAR Wire Service