KANSAS CITY, Kan. -- NASCAR has overhauled the Sprint All-Star Race to try to create excitement in the event by forcing the leaders to pit for tires prior to a final 13-lap segment.
The All-Star Race, held May 21 at Charlotte Motor Speedway, will consist of 113 laps divided into three segments.
* The first 50-lap segment will require drivers to make a minimum two-tire pit stop under green. The drivers will then be required to do a minimum two-tire pit stop during the first break and start the second segment the way they come off pit road.
* The second 50-lap segment will require a minimum two-tire pit stop under green before Lap 85 (Lap 35 of the segment). There will then be a draw to determine whether the first nine, 10 or 11 cars will have to do a four-tire pit stop during the break while the remaining cars will not be allowed to pit. The cars that pit will line up behind the drivers who weren't allowed to pit.
* The final 13-lap segment will count only green-flag laps. The idea is that cars on fresh tires will have to fight their way to the front over those 13 laps.
The format was developed with the help of the Sprint Cup Drivers Council, and Brad Keselowski came up with the idea of requiring leaders to pit while requiring those at the tail of the field to stay out.
"You're either going to drive through the field in 13 laps, which in my belief is earning it. Whenever you have to pass 12 or 13 cars over the course of 13 laps is a lot of passing," Keselowski said. "That's going to require perfecting from a driver making all the right moves and understanding every little idiosyncrasy of the racetrack and his competitors.
"And if a guy [with old tires] gets the lead and runs away with it, he's going to have to drive his butt off because he's going to have such a natural disadvantage. ... Either way, no matter who wins, you're going to have fight hard. When we looked at the last few years' scenario, it was pretty simple: win the restart into Turn 1, win the race."
The event will have at least 20 drivers. Fifteen drivers have already qualified, while three more will advance out of the May 18 Sprint Showdown race. If any driver who hasn't won since the start of 2015 wins in the next two points races at Kansas and Dover, he or she will earn a spot. Otherwise, one or two drivers will get in through a fan vote.
The 15 active drivers who already are in the race are 2015-16 winners Kurt Busch, Kyle Busch, Dale Earnhardt Jr., Carl Edwards, Denny Hamlin, Kevin Harvick, Jimmie Johnson, Matt Kenseth, Joey Logano, Martin Truex Jr. and Keselowski, plus past All-Star winners Tony Stewart, Jamie McMurray, Ryan Newman and Kasey Kahne.
The Sprint Showdown is divided into three segments, with each segment winner advancing to the All-Star Race. There will be a minimum two-tire pit stop between the segments, which will be 20 laps, 20 laps and 10 laps.
The Associated Press contributed to this report.