The NASCAR X-FINITY Series also runs on the three-quarter-mile Fairgrounds oval with tonight’s Virginia529 College Savings 250.  Junior Motorsports has won the last two races contested there, with Chase Elliott last fall and Dale Earnhardt Junior earlier this season.  Neither driver is entered this weekend, with Elliott concentrating on his Sprint Cup duties and Earnhardt still recovering from a concussion.  Justin Allgaier, Alex Bowman and regular-season points leader Elliott Sadler make up the Junior Motorsports lineup for this weekend.  With just two races remaining in the regular season, Sadler is battling rookie Erik Jones for the top seed in the inaugural X-FINITY Series Chase.  He has two victories thus far, one less than Jones … Earlier this season, Sadler finished third at Richmond while Jones was sidelined by an accident and settled for thirty-fourth place in the forty-car field.