Few deny that the International Baccalaureate (IB) program that started at Washington-Lee High School eight years ago is going well.

But some fear that the rigorous program -- which trains students for an internationally recognized diploma -- is going so well that it is draining high-achieving students from other high schools, particularly Wakefield, which lost 34 IB students to Washington-Lee this year and 39 last year.

Tonight, the Arlington School Board will vote on a proposal that aims to stop the brain drain by limiting the number of new IB transfers into Washington-Lee and requiring transfer students who change their minds about taking the IB program to apply for permission to finish their schooling at Washington-Lee.

The proposal, meant as a stopgap measure while the board studies the issue, would limit new IB transfers to 27 next year, the same number of senior IB transfer students graduating from the school. It would do the same with non-IB transfers, limiting them to 18. If more than 27 students apply to IB (last year, for example, 45 students transferred into IB from the Wakefield and Yorktown areas), access would be granted by lottery.

Arlington School Superintendent Robert G. Smith said the transfer limit is necessary because Washington-Lee is over capacity. "If we were following the [district's] regular guidelines, we wouldn't be accepting any transfers," he said.

The question of limiting access to IB -- an alternative to the college-level Advanced Placement (AP) courses -- has angered some parents who say it would hamper a successful and growing program. Parents of IB students also object to an idea discussed at a recent School Board meeting that would require transfer students who want to take IB to wait until 11th grade to transfer to Washington-Lee rather than start there in ninth grade as they now can do.

Christopher Prins, whose daughter Emma transferred in ninth grade from the Yorktown district into Washington-Lee's IB program, said students like her would be unlikely to choose IB if it meant changing high schools in 11th grade and leaving behind friends, sports teams and clubs.

"[The plan] would preclude kids from attending unless they switch schools midstream, which is absurd and would functionally undermine and destroy the IB program," he said.

But those seeking to limit IB transfers point out that many eighth-graders who transfer into Washington-Lee thinking they will pursue an IB degree change their minds by 11th grade, when most IB courses begin. Even so, they tend to stay at Washington-Lee to finish their schooling. Wakefield parents say that jeopardizes Wakefield's highly regarded AP Scholars program by drawing potential AP students to Washington-Lee.

Cathy O'Malley, whose daughter Nina started at Wakefield last year, said nearly all her daughter's friends opted to go to Washington-Lee, a trend that concerns her. "When you lose essentially two classrooms full of high achievers, half of whom are minority, that skews the SOL [Standards of Learning] scores and SAT averages for the school, because you have fewer at the higher end balancing the score," she said.

Brenda Pommerenke, vice president of the Wakefield PTA, said the departure of high-performing students can lead to a downward spiral for a school that some top students are already leery of attending.

"There is angst in certain corridors about sending a Caucasian child to a largely non-Caucasian school," Pommerenke said, adding that some people opt for IB simply to get out of attending Wakefield. "The real tightrope here is, how do you have an IB program available to students who really want to be in the IB program versus how do you address students who are trying to escape a situation that they really don't know a lot about."

School Board Chair Libby Garvey said the 11th-grade requirement that has upset parents is unlikely to be implemented. But she said the current system is unfairly weighted toward Washington-Lee, which offers both IB and AP courses, and needs to be changed.

"You have one school that has everything your high-achieving students would want," she said. She added that the fact that Washington-Lee is about to be rebuilt will make it even more attractive to prospective transfer students.

Board member Elaine S. Furlow said she is reluctant to limit IB transfers. "I don't want to look a kid in the eye and say, 'Because of where you live, you can't come to IB,' " she said.

One solution the board may consider is starting an IB program at Wakefield. That, Pommerenke said, would not be easy. An IB program requires special training, fees and textbooks, and it would require enough high-performing students to fill both the IB classes and the current AP courses. "We just don't think that people have the energy to start another program that is going to serve a very small population at the school," she said.