Latest in the world of academic credits for athletes: Billy Mullins, a Southern Cal sprinter swift enough to have run on USC's 400-meter relay team that set a national collegiate record last month, earned credits from four community colleges before he became a Trojan in 1978. Four schools in autumn 1977, one semester!

Mullins passed courses at Pasadenia, Rio Hondo, Los Angeles and West Los Angeles community colleges. He says he attended three of the schools -- West L. A. in his home vicinity, PCC and Rio Hondo 40 miles away -- and monitored a "cooking class" to gain credit from L.A. CC. The hustling Mullins, saying he also got credits from summer classes at California Lutheran in Thousand Oaks, allows:

"I worked my butt off. I stayed up late at night. . . I did a lot of driving."

College hoopster of the year, say NBA executives and scouts polled by Sporting News: Louisville's dunkin' Darrell Griffith -- by one vote over De Paul's Mark Aguirre, with O'Koren, Macy and Caroll rounding out big five . . . Durand Macklin, LSU's potent 6-7 forward eligible for the pros in '80 because his class graduates this year (he missed last season hurt), says he will stay at Baton Rouge another year -- "it's more important to get my degree" . . . NHL swap: Jerry Korab, the defenseman of six years' Buffalo service, from Sabres to L.A. Kings for first-round choice in the 1982 entry draft. . . Nolan Richardson takes his Western Texas J.C. club into the national JuCo basketball tourney in Hutchinson, Kan., next week with a 33-0 record -- and a step up to look forward to: newly named to coach Tulsa University, as the first black to direct a major college squad in Oklahoma . . . Scratch the NBA rumors, Denver Nuggets evidently going with Donnie Walsh as coach again next year. Reorganization at the upper levels, but Carl Scheer stays on as president-g.m. and says he wants to go with Walsh . . .