Jill Sanders Plumb and Dylann Duncan are in the homestretch of their storied BYU volleyball careers, but they're finding their finish a little frustrating.

The two four-year starters - BYU's all-America bookends - play their final match on the home court tonight as the Cougars host Arizona in a first-round NCAA playoff.It's not like they're leaving unfinished business, having combined to be what BYU Coach Elaine Michaelis calls one of the best college pairs to play together in the same four-year period as evidenced by BYU's 133-28 record 28 during that time.

"What an awesome twosome to have go together," says Michaelis of the two former Salt Lake City multi-sport prep standouts.

Duncan, a 6-foot-3 middle blocker, already held Cougar career records in kills, block assists and total blocks going into her final season and set an NCAA standard in career kills (2,146) last week. Following the '87 season, she made second-team all-America and first-team academic all-America and was invited to the U.S. national "B" team last summer.

This year, the fifth-year senior is the only player ranked among the nation's top 10 in three per-game statistics - kills, aces and blocks. She also leads BYU in hitting.

Plumb earned first-team all-America last season while pacing the Cougars in kills and hitting percentage. This year, she's tops on the team in digs and second to Duncan in hitting percentage.

However, Plumb and Duncan will conclude the season and their college careers with some reservations.

Plumb is playing well below her performance level of last year, Duncan is has fallen off her fast-paced start earlier this fall, and the BYU team as a whole is down a bit from previous seasons.

For the Cougars, it has been an "in" year - as in inexperience, injuries and occasional inconsistency. After a 21-4 record and a 12-match winning streak, BYU has been slumping a bit of late, having gone a more mortal 4-6 through its past 10 games. And the "in" problems carried over to the setter position, left vacant by consensus all-America Mariliisa Salmi after she completed her three years of eligibility.

Plumb has suffered the biggest letdown from Salmi's absence; the spectacular setting in past seasons made Plumb a nearly unstoppable outside hitter. However, the Cougars have had to return to a more fundamental offense - set it high for Duncan. That made Duncan the dominant force in '88 rather than Plumb.

"Dylann has the spotlight this year; I had it last year," says Plumb, with little disdain. That underscores Michaelis' claim that the team has no egos or conflicts.

Despite having her number called more often, Duncan isn't without her problems. Six weeks ago, she suffered stress fractures in both lower tibias - she hasn't practiced since and admits her strong showing early in the season canceled out some average performances of late to keep her in the national statistic rankings.

Michaelis describes Plumb as naturally talented in many areas, varying from athletics to cooking to music. Duncan is not as gifted athletically, but she makes up for it by working twice as hard. "You just don't find a pair like that come along - and have them be Utah kids as well," Michaelis says.

Both were standout prep basketball players - Duncan at Highland and Plumb at Skyline - who took up volleyball midway through their high school years as a fall diversion and a way to maintain conditioning.

While Plumb was recruited heavily in both sports, Duncan shunned some 50 major-college basketball programs to play at BYU - the only university to recruit her in volleyball. The key was to show the two that while they might end up as also-ran hoopsters, they could use their size to star in volleyball.

After the season, Plumb expects to reunite with a husband working in Hawaii rather than taking a possible national-team invitation.

That's where Duncan will be this summer, having opened eyes as well as doors during her "B" team experience after an auspicious beginning.

Erroneously expecting to be offered equipment during her three weeks at the national facilities in San Diego, Duncan ended up borrowing shoes from the national coaches. "I'm sure they were really impressed from the start," she laughs.

She impressed during a three-match stint against West Germany. Getting her first playing time in a game when the U.S. was down 12-2, Duncan's jump serve and strong frontline play helped the team win.

A strong showing on the national team this summer and an August appearance in the World University Games in Brazil could aid Duncan in achieving her goal of playing in the 1992 Olympics.

However, strong individual performances by both Duncan and Plumb in Friday's playoff against Arizona as well as a total team effort could erase some 1988 frustrations and put the two one step closer to leaving BYU on a winning - and personally satisfying - note.