"I know that I am good enough to drive the car as fast as I need to go. I know how to make the right decisions, I know how to win a race, I know how a championship is won," he said. "I am not making ignorant mistakes every week to the point where I'm going 'Wow, what the ... is up with my focus?' But I did lose a lot of confidence if I would ever get back.

"Not 'Can I get it done?' but 'Am I ever going to run good again, ever? What if this is it?' And you're still wondering until you get it turned around."

So Earnhardt, often criticized for lackadaisical effort, is putting 100 percent into his race team. Those close to him say his commitment has never been greater, and the other three Hendrick drivers have found him to be an engaged, dedicated teammate.

For Hendrick, working with Earnhardt has been far easier than he ever imagined it would be when he signed him to a 5-year deal after Earnhardt had decided to leave his late father's race team, Dale Earnhardt Inc., at the end of the 2007 season.

"When I first thought about him coming over, a lot of people in this garage said 'Good luck handling a superstar,' " Hendrick said. "But everything I've asked him to do — whether working out, eating better, or showing up at the shop — he's all over it. He wants to do his part. He's much easier than I thought he would be.

"I couldn't ask him to work any harder than he's working. I don't care what anybody says. He's committed. He's dedicated. And he's showing up and he's trying. That's all I can ask him to do."

Earnhardt had this current three-race stretch leading into NASCAR's off weekend circled as his time to click with McGrew and really turn things around. He was an improved 13th last week at New Hampshire, is always a threat to win at Daytona, and a recent tire test at Chicago has him encouraged about next weekend's race.

And he's vowed not to let up until he's back on the right track, racing for wins and his first Sprint Cup title.

"I could work out more than Mark, I could ride a mountain bike farther than Jimmie and I could try to invent a new international language for explaining how a race car drives. There's all kinds of things I can do differently," he said. "Making the Chase is going to be (really) hard. I know it. But we've still got a shot until they say we don't. If that doesn't happen, I need to end this year saying 'We have repaired it, we have fixed it, this is the direction we're going and it's going to be fine.' "