It was like saying no thanks to birthday cake. Big, thick, gooey pieces of birthday cake. And Al Bumbry just couldn't resist.

For years, American League Pitchers fed him a steady diet of rich, gooey fast balls, high and inside. Bumbry would try to clean the plate with them and end up flying out to left field. "It was like eating too much cake," he said. "You know it's not good for you, but it's there and it looks so good, so you nibble at it."

This year, Bumbry has been passing up those pitches, taking the base on balls.They're still tempting. But now, Bumbry says. "I'm watching my figure."

The Orioles chief nutritionist, Earl Weaver, has watched as Bumbry has fattened his batting average to .308 and raised his on-base percentage to .399. f

Last year, it was .338 (lifetime .346). The improvement, Manager Weaver says, is one of the reasons Bumbry, who never had more than 50 at-bats against left-handers before 1977, is staying in the lineup.

Going into last night's game, Bumbry had 64 walks, 19 more than his career high, and had scored 82 runs, two more than all of last year. "I'm going to score 100 unless I fall flat on my face," he said. "And I don't intend to do that."

"Al's done a good job, an exceptionally good job of getting on this year, laying off that pitch." Weaver said. "It's the first year that you could notice a definite effort in that direction. He finally realized that some advice he's been getting for years might be beneficial."

Bumbry says, "When I look back I wonder why the hell it took me so long. I guess it's like if someone said ice cream is good, or sex is good. Until you experience it, you aren't convinced."

Besides, he was rookie of the year in 1973 and hit .337. "I never said this game was easy, but . . . what the hell did I need a walk for?" Bumbry said.

In 1974, pitchers began moving the ball up and in on him and he slumped to .233. "You would have thought I would have listened," he said. "Move it up six inches and it's a ball. But you can't tell the difference until you miss it."

This year, he listened to Batting Coach Frank Robinson and that has made all the difference. Robinson said, "The main thing was that he would be down in a crouch but he would come up on his stride. So the ball up high looked good to him. If you stay down the ball will look high."

The turning point came two years ago in spring training when Bumbry got only one walk in the Florida sunshine. "Earl said it was pathetic," Bumbry said, "and it started me thinking. So this spring I wanted to lead the club in walks. I had nine for 60 at-bats, and someone else was nine for 30. Earl told me I wasn't leading the club because the other guy's percentage was better. It ticked me off. I felt I had something to prove." p

And that he has. The diminutive center fielder, who puts to go in the Go Orioles cheer, has been running on high octane all season, even while the rest of the Orioles were stalled.

Friday night was Bumbry's season in a game. The Orioles lost, but Bumbry, who was three for five with a home run and a double, kept them in it just as he kept them in it early this season. His third hit knocked Tommy John out of the game.

Two weeks ago when the Orioles were in New York, Reggie Jackson compared the matchups of the two lineups, beginning with the leadoff men Bumbry and Willie Randolp. "Randolph will get a few more walks," Jackson said. "Bumbry will have a little higher average. Both will steal a base. It's a push."

And so it was Friday night. Randolph hit the first pitch of the game for an opposite-field home run and circled the bases with his first clenched high in the muggy air.

In the bottom of the inning, Bumbry responded with a home run to the deepest part of left center field that said "Not so fast" to the Yankees. An exultant fist would have been superfluous and out of character. "That's not my style." Bumbry said., 'I felt that way but it's not my style to show it."

But when he struck out leading off the eighth, Bumbry dejectedly kicked a crushed cup back to the dugout, like a kid kicking a stone. "An emotion of disgust," he said. "I show that more than happiness."

Bumbry is a hard man but only on himself. Friday night, he said, "was just an example of the way it's been this season. I got some hits and we lose. I can't go around smiling about that."

Bumbry's three-year contract with the Orioles expires at the end of next season. He says he hasn't given it much thought. "I have to tell my lawyer to cool it," he said. "I get two or three hits, oh, does he get excited."

Right fielder Ken Singleton one of several Orioles who were cold this spring while Bumbry was hot, was asked what "The Little Boomer" meant to the team. "Well," he replied "Where did we finish the year he broke his leg? Fourth?"

Bumbry missed nearly four months of the 1978 season after breaking his left leg while sliding back into second base. He came back last year and batted .285 with 37 stolen bases.

"Al's very popular on the team," said pitcher Steve Stone. "Athletes have a very special feeling for a man who comes back from the type of injury that can end a career. They respect his determination and ability."

In the third game of the American League playoffs last year, Bumbry dropped a low line drive that allowed the California Angels to win the game. The next day before the game, one of his teammates said confidently, "We're not going to lose. Because of Bumbry. We don't want him to have to live with that."

Bumbry, who has never been one to seek the limelight, "would have been very well-known, known as the guy who dropped the ball and gave the game to California." The Orioles did not want that for him.

Bumbry is nothing if not conscienctious. During his nine months as a platoon leader in Vietnam, he did not lose a man. As a baseball player, "Bumbry has worked harder than any one to make himself a good outfielder," Weaver said. "Now the team suffers defensively when he is not playing."

"No one has mentioned Paul Blair once to me this year." Bumbry said smiling. (Blair was the Orioles fine-fielding center fielder before Bumbry).

Early this season, after a particularly disheartening 11th-inning loss, Bumbry, then leading the league in hitting, stood in the lobby of Memorial Stadium, unnoticed as disgruntled fans rushed by him. "If i'm in a crowd of people, I stay in the crowd," he said. He does not go out of his way to attract one. Or to attract publicity.

Friday night, the Orioles allowed a reporter to sit and talk with Bumbry in the dugout during the pregame rain delay. "It's okay," said Doug DeCinces, "because you're talking to the All-Star." (It was hif first All Star appearance).

When the rain began, Bumbry was the only Oriole who stayed on the field signing autographs.

Bumbry has a slight speech impediment (an occasional stammer), but it does not prevent him from expressing himself with considerable eloquence and sensitivity. It is enough however, to make him "shy and insecure," to make him avoid a lot of publicity "To keep from embarrassing myself. I shy away from it," he said.

"One reasoin I'm shy and insecure and have a speech problem is because of my childhood," he said. "My parents never married. My mother lived in one section of town and my father lived in another. When I was young, I lived with my father but I wanted to live with my mother. It created some conflicts in my mind.

"Now my daughter is going through the same thing. My wife and I are separated. I can sympathize with her (his daughter's) fellings because I went through the same thing as a child."

His daughter's name, Tehia, is on his license plate, "My Little Lady," he said.

John Blake, the assistant director of publicity for the Orioles, said, "Al does more personal-speaking appearances than anyone on the club. He's always the first to volunteer. He's so courageous."

There is no impediment to class.