What to watch: •Men's basketball: In an ACC showdown, No. 6-ranked Duke hosts No. 1 North Carolina at 8 p.m. Saturday on ESPN (Dan Shulman and Dick Vitale). The Big 12 regular season wraps up this weekend as OU hosts Missouri at 2:30 p.m. Saturday on KOCO-5 (Terry Gannon and Fran Fraschilla), and OSU plays at No. 5 Texas at 3 p.m. Sunday on ESPN (Ron Franklin and Fraschilla). Other Saturday telecasts include No. 5 Kansas at Texas A&M at 3 p.m. on KWTV-9 (Jim Nantz and Billy Packer) and KOCB-34's doubleheader of Baylor at Texas Tech at 12:30 p.m. and Kansas State at Iowa State at 3 p.m. and. •Prep basketball: The large school state championships from Ford Center are featured on KSBI-52 with four semifinals today (4:30 p.m., 6A girls; 6 p.m., 5A boys; 7:30 p.m., 6A boys; 9 p.m., 6A girls) and four finals Saturday. (1:30 p.m., 6A girls; 3:15 p.m., 5A boys; 7 p.m., 5A girls; 8:45 p.m., 6A boys). Robert Allen, Bob Cortes and Chris Johnson are the announcers. •NBA: The Hornets play at surging Houston at 7:30 p.m. Saturday on NBA TV. San Antonio goes on the road to play Denver at 9:30 tonight on ESPN and Phoenix at 2:30 p.m. Sunday on KOCO-5. •Auto racing: Jimmie Johnson will try to become the first driver to win three consecutive races at Atlanta Motor Speedway in the NASCAR Sprint Cup Kobalt Tools 500 at 12:30 p.m. Sunday on KOKH-25.