Amid concern over a lack of NCAA Tournament at-large bids in two of the past three years, ACC athletic directors plan next month to discuss expanding the conference men's basketball schedule to 18 games.

ACC teams have played a 16-game conference schedule since 1991-92, when Florida State was added to the league. The Big East, Big Ten and Pac-10 played 18 conference games last season.

N.C. State athletic director Lee Fowler said the ACC needs to explore the possibility of joining them after the conference had the nation's top RPI ranking going into the 2008 NCAA Tournament but got just four berths.

"There's no question, it concerns me, and [ACC commissioner] John Swofford, and everybody else," said Fowler, a former chair of the Division I men's basketball committee.

ACC athletic directors are expected to discuss the issue at the conference's spring meetings, May 11-14 at Amelia Island, Fla. A year ago, they considered expanding to 18 conference games but shelved the idea because of strong opposition from ACC coaches.

The coaches have been wary that 18 conference games would make their schedule too challenging and cause them to be reluctant to schedule attractive non-conference games.

Virginia Tech coach Seth Greenberg, whose team was left out of the NCAA field despite a 9-7 ACC record, said coaches need to have open minds about 18 conference games.

In two of the past three years, just four of 12 ACC teams have been selected for the NCAA Tournament.

The ACC's total of 19 NCAA Tournament wins from 2006 to 2008 is an all-time low for a three-year period since 1979-81, which was before the tournament expanded to 64 teams. The Big East, Pac-10 and Big Ten, which all play 18 conference games, got higher percentages of their members into the NCAA Tournament in 2008.

Jerry Palm of collegerpi.com said his studies have shown that playing 18 conference games actually hurts a conference's RPI. Palm is an expert on the RPI (Ratings Percentage Index), a formula that includes won-loss record and strength of schedule. It is used by the Division I men's basketball committee to compare candidates for the NCAA Tournament.

"Going to two extra conference games has a general negative impact on RPI, because what usually happens is everybody takes two wins [over weaker opponents] off their schedule, so everybody's overall record is lower," Palm said.

But he said playing 18 conference games might have helped Virginia Tech in 2008. The Hokies didn't defeat a top-50 team until the ACC Tournament, and their lack of top-50 wins was cited as a reason they were omitted from the NCAA field.

Virginia Tech didn't play home games against Clemson or North Carolina last season. Adding one or both would have given the Hokies an opportunity for at least one top-50 win.