AVONDALE, Ariz. – ThorSport Racing’s Grant Enfinger will start first when the NASCAR Gander RV & Outdoors Truck Series closes its season Friday night at Phoenix Raceway.

Enfinger earned the top spot by virtue of NASCAR’s performance-based metric formula.

The NASCAR matrix factors in a driver’s lap speed ranking from the previous race, the last race finish for both driver and owner and the car’s current rank in the owner standings.

Lap speed is weighted at 15 percent, previous race finish at 25 percent for the driver and owner results and owner points position at 35 percent to calculate the final metric score.

Driver and owner playoff-eligible entries are ranked at the front of the field based on their metric scores from lowest to highest, with all non-playoff entries lined up behind the playoff cars in similar fashion.

Enfinger took the pole with a metric score of 2.55, factoring in his Martinsville Speedway win from last weekend, the ninth-fastest lap from that event and his second-place seeding in the current point standings.

GMS Racing teammates Zane Smith, Sheldon Creed and Brett Moffitt will start second through fourth, respectively, in their quests for the Truck Series crown.

Matt Crafton, one of Enfinger’s teammates at ThorSport, starts best among the non-championship-eligible drivers in fifth.

To view the complete starting lineup and performance matrix breakdown, click here.

The Lucas Oil 150 is slated for an 8 p.m. ET start Friday night, with live coverage on FS1, the Motor Racing Network and SiriusXM NASCAR Radio, channel 90.