Five to Watch: All-Star Race at Charlotte

The Monster Energy NASCAR All-Star Race (8 p.m. ET, FS1, MRN, SiriusXM) has extra layers of intrigue this year, owed less to shifts in the race format than to enhancements to the cars themselves. The ultimate prize -- $1 million -- remains the same in the annual non-points event, but other variations are planned at Charlotte Motor Speedway to shake up the show. With uncertainty still looming over how the invitational event will play out, here are five story lines to watch for NASCAR's annual All-Star weekend.

HEAVYWEIGHT FIREWORKS: Kevin Harvick and Kyle Busch rank as the only drivers with multiple wins in the Monster Energy Series this year, so it stands to reason that the two could face off in the late stages with $1 million on the line. Busch was prodded during his Friday media session to envision such a scenario, with full-contact racing standing out as a possibility. Though he didn't quite bite, he did conjure up imagery of the 1989 All-Star Race where Rusty Wallace and Darrell Waltrip found themselves at odds after the incident known as 'The Tide Slide.' 'It’s just, there's no telling,' Busch said Friday. 'If you’re looking for a Rusty Wallace, DW-type moment for me to say, then sure, have it, I guess.'

ALL THE STARS FOR HARVICK: Kevin Harvick has just one All-Star Race win, back in 2007 for Richard Childress Racing. But given his recent tear through the Monster Energy Series competition, the 42-year-old driver may be primed for another victory in the annual invitational. Five wins in the first 12 points-paying races of the 2018 season easily elevate the Stewart-Haas Racing No. 4 Ford team to the top rungs of the favorites list. Squelching the All-Star drought remains a strong possibility.

RULES REDUX: A combination of aerodynamic changes to the rear spoiler and front splitter, the addition of air ducts and an engine restrictor plate are designed to close up the competition on the 1.5-mile track. The racing it's expected to produce could resemble a dense Daytona/Talladega pack, last year's Xfinity Series event at Indianapolis with a similar rules package ... or something in between. Only time will tell, with more answers set to be unlocked in the Monster Energy Open/All-Star practice on Saturday and the 80-lap main event.

WEATHER OR NOT: Friday's rain played havoc with the on-track schedule, making Monster Energy Series practice a case of fits and starts. No driver turned more than five laps in the abbreviated session and most completed either one lap or none. The limited track time threatens to throw another curveball to the teams in an already nebulous race weekend. Teams already qualified for the All-Star Race will likely take an even keener interest in the Monster Energy Open and the type of racing it produces.

FOR THE FORMAT: The race will once again be split into four stages, but mandatory pit stops, softer tire options and average finish calculations are out. Stage 1 is scheduled to end at Lap 30, Stage 2 at Lap 50, Stage 3 at Lap 70, and a final shootout that goes to the Lap 80 distance. Each stage will have NASCAR Overtime rules in effect, and only green-flag laps will count in the final stage. The 10-lap shootout, a nod to tradition which has been a powder-keg for highlights in years past, returns for the ninth time in the last 10 editions.