Updated: Jul 1, 2013, 1:21 PM

Sprint Cup: Jimmie Johnson still in great shape

By David Newton | ESPN.com

Superman apparently has a weakness.

Restarts.

And it apparently has gotten into his head to the point where it could play a role in his quest to win a sixth Sprint Cup championship.

Jimmie Johnson, dubbed Superman by Mark Martin in 2009, had a restart issue for the third time this season and second time in five races on Sunday at Kentucky Speedway.

It turned another dominant performance into a ninth-place finish for the five-time champion.

Johnson was so frustrated that he didn't hang around long to discuss his issues in detail -- a rarity for the Hendrick Motorsports driver -- saying only that Matt Kenseth broke the pace-car speed during a brief interview with PRN as he left the track.

Restarts have become such an issue for Johnson that TNT analyst Kyle Petty, warning ahead of time that he was being sarcastic, said, "Let's let Jimmie Johnson write the restart rules.'' But Johnson has left the door open for such criticism, something he rarely gets for anything but winning too much.

After the March 3 race at Phoenix, Johnson called out eventual winner Carl Edwards for the way he restarted the race.

Chris Trotman/Getty ImagesDon't be too concerned about Jimmie Johnson and crew chief Chad Knaus, above. The 48 team still leads the Sprint Cup standings by 38 points.

"I felt like Carl didn't follow the restart protocol and was slower than the pace car on his last two restarts, and it gives the leader a huge advantage when that happens," said Johnson, who went on to finish second in that race.

After the June 2 race at Dover, Johnson accused Juan Pablo Montoya of deliberately slowing down to force him to jump the restart that drew a pass-through penalty and turned what appeared a sure victory into a 17th-place finish.

Then on Sunday, with 21 laps remaining, Johnson accused Kenseth of breaking the pace car speed moments before he spun out after restarting second.

"We were kind of in an awkward situation in that restart there,'' said Johnson, who rallied to finish ninth in a race he led 182 of 267 laps.

"The No. 20 [Kenseth] broke the pace car speed, which you aren't supposed to, but they aren't calling guys on that so I need to start trying that in the future."

Kenseth didn't appear to do anything wrong en route to his series-best fourth win of the year. He was surprised Johnson was upset.

What shouldn't get lost in all of this is that Johnson, weakness on restarts or not, remains the driver to beat. He easily could have won four of the past five races instead of one of five.

He's led 41.5 percent of the laps -- 471 of 1,137 -- in June. Second-best is Kyle Busch with 150, and all of those were at Dover.

Kenseth hadn't led a lap in three straight races, and wouldn't have been in position to lead at the end of this one had he and crew chief Jason Ratcliff not gambled with a no-tire stop.

That's something else that doesn't need to be lost. Kenseth had to gamble to be in position to keep Johnson from winning. So there's no arguing the No. 48 team remains the favorite.

But the list of legitimate challengers behind Johnson is growing:

• Kenseth -- Three of his four wins this seasons have come on 1.5-mile tracks that make up half of the 10-race Chase. If the playoffs started today he'd be first, and few are known for their consistency more.

• Clint Bowyer -- At some point he needs to win to become a true contender, but his third-place finish at Kentucky gave him an average finish of 5.0 over the past three races and 7.8 over the past seven. That'll keep you in championship contention.

• Kevin Harvick -- Few have noticed because of his lame-duck status, but the Richard Childress Racing driver has seven straight top-10s to go along with his two wins. That's the kind of consistency that wins championships and makes you wonder if going to Stewart-Haas Racing next year is such a good idea.

• Kyle Busch -- His fifth-place finish was his fourth of sixth or better in the past five races, and he's capable of running off a string of wins anytime now that Toyota Racing Development appears to have found a good balance between power and engine durability.

• Joey Logano -- Don't laugh because he's on this list. His fourth-place finish moved him to 10th in points and gave him six straight finishes of 11th or better, an average of 7.6. Had Johnson not blown the restart right in front of him he had a car capable of winning.

There are several others, and many aren't in the top 10. A mere 22 points separate...

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