Five to Watch: Hottest story lines for Las Vegas race

The full-fledged debut of new rules and a heaping helping of uncertainty loom over the third race of the Monster Energy Series season, Sunday's Pennzoil 400 (3:30 p.m. ET, FOX, PRN, SiriusXM). With anticipation building in the desert, here are five story lines to watch at Las Vegas Motor Speedway.

Rules of the road: The full 2019 rules package, with increased aerodynamic downforce and reduced horsepower, will get its first go with a nearly full field in race conditions Sunday. What to expect? Perhaps a mix of wide-open, restrictor-plate-style racing with aero push and pull, but with momentum and handling still playing a factor. A January test and this weekend's preliminary track time may not fully shape the predictions, but several drivers are counting on intensity and the prospect of drafting on a 1.5-mile venue. "I think the level of anxiety is going to ratchet up this weekend versus what it was at Atlanta," said Vegas native Kurt Busch, who starts 28th.

RCR's resurgence: The hot hunch in the Las Vegas garage points to Richard Childress Racing among the largest gainers from the change in rules. Drivers Austin Dillon and Daniel Hemric stand to benefit from the organization's diligence, and both start inside the top five on Sunday. The two drivers also ranked 1-2 in both practice sessions. "I felt like we left the Vegas test as the fastest car and I wondered how we would come back," Dillon said, "and I felt like we brought the exact same speed back."

Teamwork in play?: The suggestion that Sunday's race might draw some parallels to pack-style racing also raised the possibilities of organizations and manufacturers teaming up mid-race. The scenario played out in Friday's Busch Pole qualifying, but may not necessarily be easy to execute in Sunday's main event. "In the race, track position changes, so it's a lot harder to organize something like that," said Paul Menard, who expects to lean on Ford loyalties and the Wood Brothers' alliance with Team Penske. "but you always kind of know where your teammates are, your friendly cars are, and try to help them out if they can help you out."

Bad-fast Brad: The advent of a significantly different rules package may dismiss the track's history as an indicator of success. Brad Keselowski is hoping his recent winning ways in Sin City carry over. In the last six Las Vegas races, Keselowski has won three times, including the track's first-ever playoff event last year. There's also the potential for momentum from last weekend's win at Atlanta Motor Speedway.

Hendrick hopes: After managing no better than a 15th place last weekend at Atlanta, Hendrick Motorsports' four-car fleet aims to rebound in Vegas. The organization made modest gains in qualifying, with three drivers among the top 12, led by Jimmie Johnson starting ninth. "Atlanta exposes mechanical grip issues more than any other mile-and-a-half (track) that's out there," said Johnson, who boasts the best Vegas driver rating since the stat originated in 2005. "Here, it's much more forgiving, the tire wear isn't as bad and tires hang on a lot better. So I think we'd be better in general, but we did change quite a bit from Atlanta to Las Vegas."