TV Ratings: Sonoma, Las Vegas, Singapore

The Monster Energy NASCAR Cup Series playoffs opened Sunday afternoon in Las Vegas, earning a 1.3 rating and averaging 2.1 million viewers. That's down a tick from last year's playoffs opener held at Chicagoland Speedway on the same weekend, which scored a 1.4/2.3m.

The NASCAR race led directly into the championship finale for the Verizon IndyCar Series from Sonoma, early Sunday evening for East Coast viewers on NBCSN. The telecast scored a 0.38 rating and averaged 629,000 viewers, an increase from last year's 0.33/528,000, also on NBCSN.

The NASCAR Xfinity Series race from Las Vegas scored a 0.49/832,000 late Saturday afternoon on NBCSN. Last year's race on this weekend (again from Chicagoland rather than Vegas) scored a 0.53/807,000.

Meanwhile, NBCSN earned 1.24 million viewers for last Monday's postponed Brickyard 400 at Indianapolis. Last year's race -- which started on its scheduled Sunday in July and on the NBC broadcast network rather than NBCSN -- averaged 5.6m viewers.

Formula 1 was back in action under the lights in Singapore, and posted a fairly typical rating for its early morning time slot -- a 0.32 -- and averaged 469,000 viewers. Last year on NBCSN, this race had a 0.28/450,000.