Rookies and major injuries make this week's Atlantic Coast Conference basketball tournament as wide open and unpredictable as any of the previous 23.

A legitimate case can be made for any six of the six of the seven ACC schools winning the annual three-day tourney starting Thursday in Greensboro, N.C. It rewards the champion (unless it is Clemson) with an NCAA bid and fills the conference schools' scholarship coffers.

The reason that six teams - all except Duke - can win the tournament rests with the unusual number of starting rookies (nine) and with a series of injuries that have struck key personnel. North Carolina is the favorite, but the apparent loss of 6-10 center Tommy LaGarde makes the Tar Hells vulnerable.

Only Clemson has neither a major injury nor a rookie starter. But the Tigers and ineligible for NCAA play because they are on probation for recruiting violations.

Today's injury report: North Carolina - LaGarde has virtually been declared out; Maryland - Steve Sheppard, 6-5 forward who missed the last eight games with an achilles tendon injury, is available; N.C. State - starting guard Brian Walker is "very doubful" with a knee injury; Duke - guard Tate Armstrong still has a cast on his right wrist and Blue Devil officials are "99 per cent sure" he won't play.

Here's a capsule look, in order of regular-season finish, at the teams: NORTH CAROLONA

Record: 9-3 ACC, 22-4 overall

The Tar Heels can win because they have the best defense in the league by far a gambling, trapping defense that produces turnovers and easy fast breaks - because of the experience of Phil Ford, John Kuester and Walter Davis, and because they have a superb, pressure-playing freshman in 6-7 forward Mike O'Koren.

The Tarr Heels' liabilities: without LaGarde, a team that has been prone to rebounding problems is left with three freshmen alternating at center. This presents a defensive problem, too, that Smith has solved by using 6-6 forward Bruce Buckley on a small center like N.C. State's Kenny Carr. The Heels have not had to face a Tree Rollins type threat since LaGarde's knee injury. WAKE FOREST

Record: 8-4 ACC, 20-6 overall

The Deacons can win if they again show the kind of team play they exhibited before the loss of their last three games. Rod Griffin, 6-5 1/2 power forward, has moves to get an entire opposition front line in foul trouble, as he did against Maryland recently. The talent is probably no better than fourth best in league, but the players complement each other well and Jerry Schellenberg's move from guard to small forward gives Wake exceptional backcourt quickness, lacking a year ago.

The Deacons' liabilities: Griffin is Wake's only power play; opponents have been successful in working on 6-11 sophomore center Larry Harrison inside; not a strong defensive team; opponents now sag back against them, inviting them to become the team they were the past two seasons: a squad that lived and died by the perimeter jumpers of Schellenberg and Skip Brown; a one-man bench. CLEMSON

Record: 8-4 ACC, 21-5 overall

The Tigers can win because, regardless of what anyone says, basketball is a big man's game and the Tigers' "Tree," 7-foot-2 Wayne Rollins, can dominate when he is inspired, and making all-ACC first team should inspire him. Also, Clemson has the most experienced and deepest bench in the league.

The Tiger's major liability is that they don't come ready to play every night. With Rollins dominating, Clemson is the best club on paper, but the game is not played on paper. MARYLAND

Record: 7-5 ASS, 19-7 overall

The Terrapins can win because of talent and because the team should be helped considerable by the return of Sheppard, whose presence gives them more quickness and versatility. The Terps have also been helped by rookie center Mike Davis' year-end improvement.

Maryland's major problem is erratic play. The squad has yet to exhibit a killer instinct upon getting a lead and, in some games, such as those with George Washington and Virginia, was on the floor in body only. Also, without Sheppard the defense suffers and a team with a good small forward can exploit the Terps. NORTH CAROLINA STATE

Record: 6-6 ACC, 16-10 overall

The Wolfpack can win because of talent, although young and erratic like Maryland's superior quickness; the ability to blow a game open, and a wonderful pair of forwards in Kenny Carr and Hawkeye Whitney.

The Wolfpack's liabilities: erratic play and the lack of a strong defensive center. Glenn Sudhop, a 7-foot-2 sophomore, has not developed as Wolfpack coaches had hoped, hence Carr plays a lot of center, position that does not suit his talents. Walker's injury will hurt them defensively and Al Green, a starter a year ago, is still searching for his game. DUKE

Record: 2-10 ACC, 14-12 overall

The Blue Devils can't win. Liabilities: without Armstrong, Duke is a two-man club 6-11 freshmen center Mike Gminski and 6-5 guard Jim Spanarkel, who would be better playing small forward. The Blue Devils are easy prey to pressure defenses, and coach Bill Foster sacrifices a slow-tempo game, which would give his team a better shot at victory, for playing fast and thus enticing recruits. The play has worked, with Philadelphia's Gene Banks already signed. VIRGINIA

Record: 2-10 ACC, 10-16 overall

The Cavaliers can win because their game is best suited for 120 minutes for play, the length of three games. The consistent Cavaliers upset N.C. States, Maryland and Carolina on successive nights for the ACC title last year. A year ago, the Cavs had a 4-8 league record and finished sixth.

Virginia's liabilities: more injuries than any other ACC team, although everyone's back for the tournament. Bill Langloh's injured ankle still worries coach Terry Holland. Also this year the Cavaliers are missing a player of the caliber of Wally Walker, the tourney MVP in 1976. They sailed through last year's tourney without pressure. There is pressure now.