NASCAR apologises for confusion around new All-Star race format

The annual non-championship race for a $1million prize ran to a new system devised by Brad Keselowski this year.

Split into three segments, there were mandatory pitstops during and between the first two, before the leading nine, 10 or 11 drivers (depending on a random draw) had to pit for tyres then fight through those who had not been allowed to do so in a final 13-lap dash.

But the system was lambasted by many drivers after several were trapped a lap down in segment one due to Matt Kenseth waiting until the last moment to make his stop - which had to be taken under green - and then being caught out by a late yellow.

Kenseth was given a one-lap penalty, but there was no facility in the rules to bring the cars he had lapped back into contention.

"I've never been this confused in a race car in my entire life," Kenseth said.

"I hope everybody watching understands, because I have no idea what happened ever since the first car pitted."

Three-time Cup series champion Tony Stewart described the format as "the dumbest damn thing I've ever been a part of".

NASCAR's senior vice president of competition Scott Miller said the situation with Kenseth had caught organisers off-guard.

"We tried to cover all the scenarios in our preparation for this unusual format," he said.

"That cropped up and unfortunately we didn't have a mechanism to have a wave-around situation for the cars that got trapped.

"Drivers and fans were confused and it's something that we definitely have to look into with this format."

Despite the glitches, the race ended in an entertaining battle for victory between Joey Logano and Kyle Larson.

That prompted Keselowski to vehemently defend his format.

"I don't know how you can get much more compelling racing," he said, having finished second to Logano after Larson hit the wall.

"They need to get unconfused and enjoy the racing."

But with aerodynamic changes reducing downforce for Charlotte also playing a part, third-place finisher Dale Earnhardt Jr suggested the format might be a red herring.

"The intent was really positive, and the ideas were great," he offered.

"But I think the simpler we make it, the easier it is to follow.

"I was pretty confused right up until it was 13 laps to go, and then I knew 'we're racing from here to the end, and this is all the normal rules'.

"But everything before that was really out of my element.

"I just think they ought to go back to the original formats that are simple and make the cars race better.

"Gimmicks and all that stuff, trying to trick up the race, is going down the wrong path.

"The way to make the racing exciting is to make the cars exciting."