Five to Watch: Martinsville Speedway playoff race

Grandfather clock trophies, hot dogs, autumn leaves and postseason racing at Martinsville Speedway -- all sure signs of fall on the NASCAR calendar. Aside from the note of crisper temperatures in the air, there's also a near-palpable sense of pressure as the Monster Energy Series' Round of 8 takes flight. The scramble for the four Championship 4 berths starts Sunday with the First Data 500 (2:30 p.m. ET, NBCSN, MRN, SiriusXM). With the home stretch ahead, here are five story lines to watch for Martinsville.

TEMPER, TEMPER: The tendency toward amiable racing at Martinsville frequently goes out the same window as the summer breeze once the schedule hits October. Last year's classic at the .526-mile track rated on the upper registers for crumpled fenders and sore feelings. There's an outside chance of a gentlemanly 500 laps, but for the eight playoff-eligible drivers with a Championship 4 berth on the line, taking will likely outweigh giving on the generosity scale.

WILD-CARD ROUND: The Round of 16 had the Roval. The Round of 12 had Talladega. For the Round of 8, are all three races wild cards? Martinsville's tight layout often produces snap-quick reversals of fortune. Texas is prepping for just its fourth race since a repaving and reconfiguration project. ISM Raceway at Phoenix is preparing for its first race with a new location for the start-finish line as part of a massive renovation. "Every week can be a wild-card week really," said Chase Elliott. "There is enough stuff that can happen that if you are anywhere close to the front, you can end up with a shot to win."

FOUR ON THE FLOOR: Stewart-Haas Racing has three races to pull off an unlikely coup by placing all four of its drivers -- Aric Almirola, Clint Bowyer, Kurt Busch and Kevin Harvick -- in the Championship 4 bracket on Nov. 18 at Homestead-Miami Speedway. With scant elbow room left for the eight remaining contenders, Bowyer shied away from the concept that SHR's strategy has changed to every driver for himself. "A total team effort across the board is the reason you have all four cars in the Round of 8," Bowyer said. "We have half of the battle."

FOUR FOR ALL: SHR's position is not without precedent. Joe Gibbs Racing placed four drivers into the Round of 8 two years ago, with two of the four qualifying for the championship finale. Kyle Busch, one of those four in 2016, says the team dynamic changes in that scenario. "When you have four guys in there, you have four that are striving to have really, really good, solid days and the teammate game isn't necessarily teammates," said Busch, Sunday's provisional pole starter. "It's all about yourself all the time when you have all four in. Even, yeah, there's opportunity for me to get some slack cut my way by my teammates that I wouldn't necessarily ask them to or expect them to."

SPOILER ALERT: Eight drivers are pressing for a spot in the championship finale, but 32 others have designs on blocking their path to Homestead with a victory. Among those outside the playoff picture are some heavy hitters, Jimmie Johnson (nine Martinsville wins) and Denny Hamlin (five) prime among them with Team Penske's Ryan Blaney and Brad Keselowski joining Hamlin as the top qualifiers among the outsiders.