The 18th Annual Bobby Martin Memorial USCS Flip Flop 50 concludes with one of the most unique formats in sprint car racing at Riverside International Speedway.

Saturday’s program features Last Chance Qualifying followed by two 25-lap USCS Sprint Car A-Mains, each paying $2,500 to win. The starting lineup is inverted for the second feature, forcing the first-race winner to start 22nd.

A driver who wins both features earns an additional $2,500 bonus, creating a potential $7,500 sweep. Derek Hagar is the only driver to accomplish the feat, completing the sweep in 2024.

Winged 600 Mini/Micro Sprints, Riverside Modifieds and the Mid-South Street Stock Challenge complete the finale program.