STWes Unseld first saw Seattle's Marvin Webster play basketball when the young Sonic center was a ninth-grader in the Baltimore School system.

"I've been following him ever since," said Unseld, the Bullets' 10 year veteran who lives near Baltimore. "I'm proud of him. He's turned into quite a ballplayer. I think he's going to be a great one."

But Unseld's pride in Webster's development hasn't interfered with the way he has been defensing the former Morgan Star star during this NBA championship round.

Unseld has combined considerable guile, a large dose of body-checking and a dab of experience to control Webster in two of the series' four games despite giving away quickness and six inches in height. Both times that Unseld has won this center matchup, the Bullets have won the contest.

The Bullets' chances capturing game five tonight (9 p.m. WTOP-TV-9) and taking a 3-2 edge back to Washington for game six Sunday will hinge greatly on whether Unseld can continue for a simple 10-foot jump shot, Unseld has been powerless to stop him.

But too often for Seattle's liking Webster has either tried to drive by Unseld or move across the middle for a sweeping hook shot.

In either case, Unseld's bulk has proven too large an obatacle for Webster to overcome. He tends to bump into the Bullet center, gets knocked off balance and either walks or misses of the shot.

Unseld also has benefited from the tendency of Seattle's trip of talented guards - Fred Brown, Gus Williams and Dennis Johnson - to forget abour offensive patterns a nd take the first open jump-shot opportunity that comes along.

Webster often goes long peiods during games without touching the ball on offense while the guards toss up 20-footers. In those stretches, his only points come from tap-ins and follow shots.

Unseld downplays his success against Webster, claiming that he isn't "doing anything differently than that I normally fo against anyone."

But against a less experienced opponent those "usual" tactics seem ideal. Unseld will bump and shove and pressure Webster constantly, never letting ghim move freely without some sort of contact. Bullet Coach Dick Motta is convicted that Webster is feeling the results of this puninishment.

"He's not as weak as people thinking but he isn't as strong as Wes," said Motta. "Wes can wear anyone down. You try getting bumped by him for 48 minutes. The next day your body is going to feel it."

Unseld has spent his NBA career dealing with the problem of offsetting the height advantage of rival centres. He gets burned only on those nights when teams decide to go inside with their offense and work on getting shots over him.

Seattle, which has survived all season on fast breaks, quick shots and outside marksmanship, has given no indication it will alter its offense to take more advantage of Webster.

"I don't think we'll do any better if we change things," Webster said. "We aren't a one-man team I'm getting enough chances. I just have to put in my shots and work to get open more."

Webster also denies that Unseld's muscle is affecting him. "I can play rough, too," he said. "My game is that flexible. I don't like to, but if they think they can intimidate us by pushing us around, they are wrong."

He certainly hasn't let anyone stop him from rebounding. Althoug his point production has been inconsitent (17 and 20 in the Sonic wins, 10 and eight in their losses), he has had at least 12 rebounds in every game, with a best of 15 ingame for Tuesday a best of 15 in game four Tuesday night.

He also is patrolling the middle on defense, blocking shots and preventing penetration by the Bullet guards. Washington tried to offset those tactics in game four by having Unseld and backup center Mitch Kupchak shoot more.

The result was series-high outputs from both. Unseld, who had scored a total of only 14 points in the first three contests, had 15 while Kupchak showed signs of emerging from a shooting slumps with 12.

"If Webster is going to wander, we have to burn him," said Motta. "We have to find the open man everytime to keep Seattle honest. I thought we did a better job of that near the end Tuesday."

The Bullets also did a better job of what Motta terms "executing the things that got us this far in the first place" during the last 17 minutes if the fourth contest.

He is taking that spurt as an indication, "We are finally ready to get back to the way we beat San Antonio and Philadelphia: total team involvement, running the court, playing giid defense.

"Up to the fourth quarter of that game, I don't think we had played even one quarter as well as any quarter in those two series. We were too loose that first quarter of game one and then we lost and we overreacted to some things and overemphasized getting the ball inside.

"The result was we got out some stuff and it's taken us this long to get it back. But I feel good now. I asked in game four if the real Bullet team would please show up and it finally did."

Motta's flexibility tonight will be determined in part by how well 'Kevin Grevey's sore hip holds up. The guard's latest injury did'nt prevent him from practicing yesterday, although he said it was "sore to the touch."

He will start but he won't find out "until I get some contact how bad it really is. Once I get running, I'll know better."

With Grevey scoring early and Charles Johnson and Larry Wright hitting from the ourside in the late going of game four, Washington's front court found it easier in shoot. Elvin Hayes says the Bullets will win to night if that trend continues.

"The films show that Seattle's guards are'nt really playing defense," he said. "But if our guards start shooting again, they have to be more honest.

"I think this series has finally settled down. We see what we have to do to win. It's up to us execute, so we can go back home Sunday and win the whole thing."

The Sonics' John Hohnson has a sore neck but is expected to start . . . The Sonics are happy that the game will be played in the Colliseum and not in the Kingdome. The sound in the doomed stadium was muffled and the players thought it took away some of their home-court advantage . . . The Bullets have chartered a plane and will return to Washington immediately after tonight's game.