Associated Press

Tony Stewart holds the trophy after winning the Emory Healthcare 500 at Atlanta Motor Speedway.

HAMPTON, Ga. -- You can't see it, feel it or even predict how long it will stay but momentum, some drivers say, could play a role in who wins the championship.

Winner Tony Stewart and Carl Edwards have it. Jimmie Johnson is getting it, and Denny Hamlin needs it.

"I used to say it didn't matter,'' Edwards said.

After finishing second Sunday at Atlanta Motor Speedway for his seventh top-10 finish in the last eight races, Edwards has changed his mind about the value of momentum.

"Now, I'm seeing this turnaround and ... I think I understand the team more than I understand where we've been gaining,'' Edwards said. "So, for that reason, I believe in this momentum that we have, and I believe that it will apply to the future races.''

Edwards admits momentum won't prevent a cut tire or mechanical issue but that it lifts the team and that can matter for something. With the series heading to Richmond this weekend before the Chase begins, that could be critical.

It is for Johnson. Even though he's been fast lately, he's not had the results, leading many to believe he has been in a slump (his average finish was 23.2 for the seven races before Sunday).

So that made his third-place finish more valuable to his team and himself.

"It's a big confidence booster, and it might sound crazy, but for myself, for Chad [Knaus] to be in the heat of the race in the end when pit stops count, the adjustments count, strategy counts,'' Johnson said. "That's the stuff you need to be on your game with during the Chase.

"To get a good race here, to be in that moment and to feel the pressure is something we needed.''

Just as it helped Stewart, who earned his 10th top-10 finish in the last 12 races.

A fine night of racing came down, in part, to pit stops. Stewart's team was slow on its next-to-last pit stop and cost him a spot. The crew recovered on the final stop, helping him gain three positions and restart second. A fast restart put Stewart into the lead for good with 25 laps left and helped him to his first Cup victory since October.

Stewart's crew chief Darian Grubb, of Floyd, Va., said the fast pit stop was critical also to help the pit crew recover from its previous stop.

"You have to be able to [move on] because if you continue to get down, you're just going to go back in a hurry because everybody else is so close on the competition level,'' Grubb said. "You're talking about three-tenths of a second at most between the best and the worst guys [on pit road] and you've go to be at the top of that game in order to keep that up.''

One team falling is Hamlin's group. Even so, he'd start the Chase tied with Johnson for first once the points are reset since both have a series-best five wins this year.

Yet, a day after saying he hoped to build momentum for the Chase at Atlanta, Hamlin finished last when his engine blew while he ran near the front.

"I know if we had the reliability that we could win this championship,'' said Hamlin, who traded the lead with Stewart 10 times within 80 laps early in the race. "It's just been tough on us the last three years. When it gets down to the Chase, it seems like we have a lot of issues and problems with keeping our cars together and [Sunday] was just a small sign of that.''

Who's in and who's out

A look at drivers who have clinched spots in the Chase heading to Richmond this weekend where the 12-man Chase field will be set and who needs to do what to clinch the remaining spots.

Clinched Chase spots

Kevin Harvick, Jeff Gordon, Kyle Busch, Tony Stewart, Carl Edwards, Jeff Burton, Jimmie Johnson, Kurt Busch, Matt Kenseth, Denny Hamlin.

Chase scenarios

n Greg Biffle, who is 11th in points, needs only to finish 42nd or better to clinch a spot, or he can clinch a spot by getting the five bonus points for leading a lap.

n Clint Bowyer, who is 12th in points, needs to finish 28th or better to clinch a spot.