What it is isn't tennis, the federal judge decided in Omaha after disgesting studies of what happens when players use the double-strung implement popularity called the spaghetti racket.

So, Judge Albert G. Schatz yesterday upheld the right of the United States Tennis Association to outlaw the thing, it has since the International Tennis Federation barred it three years ago.

Gunter Harz Sports Inc. of Omaha, maker and marketer, sought removal of the ban and asked $2 million damages from USTA. Cliff Drysdale of the Association of Tennis Professionals testified the double layer of strings enabled a player who never could impart topspin with a conventional racket to hit great topspin lobs with just a small adjustment in stroke. Vic Braden, noted teaching pro, showed that on a typical 120-foot court with 12-foot fence, such a lob hit hard enough with a spaghetti racket could force an opponent to a 9-foot height against the back fence to return it.

Judge Schatz: "A rule on racket specifications designed to prohibit rackets which in part exaggerate a topspin . . . is rationally related to the goal of preserving the character of the game of tennis." Suit dismissed. . .

Now Bob McAdoo wants to play, and grieves to the NBA Players Association because the Detroit Pistons won't let him. The former pro scoring champ out of North Carolina claims he has been able since Feb. 14. Says G.M. Jack McCloskey: "He hasn't worked out one day since Jan. 21. . .Bob McAdoo playing the last 15 games would do nothing for the Pistons."

Look at ex-Terp, ex-CBA Brad Davis finally making it in the NBA. The 6-3 guard with the good knack for assists suddenly a regular double-figure scorer for Dick Motta at Dallas; topped a 22-point game last week with 31 against Boston Tuesday. . .Another key NHL injury: Bob Dailey lost to the Flyers; knee torn up. . .

New nomination for worst-behaved basketball fans: Wyoming's were witnessed" when Brigham Young visited Laramie last week, says BYU President Jeffrey R. Holland. Cougar players, coaches, fans allegedly pelted with rotten fruit and rocks, among other goodies. . .Fined $750 each: Ilie Nastase and Jim Delaney, who developed his tennis around Montgomery County, for a shoving match in Denver just shy of fisticuffs. Goading Nasty won, 6-3, 7-5.

NBA Commissioner Larry O'Brien issues a directive against ejected coaches relaying information to the bench. This wouldn't have anything to do with Sunday when ejected Boston Coach Bill Fitch might have cribbed the CBS telecast showing Philly's Billy Cunningham diagramming strategy?

Virginia hires two football assistants for Dick Bestwick: Colgate aide Kurt Van Valkenburgh, and Jim Cavanaugh, offensive coordinator at Marshall -- under Sonny Randle.