It was a beautiful day, the kind tourists leave places like Chicago for, the sun warm and sky cloudless. It might have been a perfect day at the ballpark but for two things:

The unlikely way the Oakland A's were playing baseball.

The way a man in the stands, obviously besotted, was critquing the way the A's were playing baseball.

"Martin," shouted the man. "Martin," he shouted again, more insistent this time, gaining the manager's attention. "Martin, you're a bum and these guys (pointing to the players on the field) are buns."

The manager, his hands dug deeply into his back pants pockets, looking just the way a manager is supposed to, answered the heckler with a disarming smile and charmed him later with an autograph.

"First one we've had all spring like that," said the manager, who's no stranger to baiters.

This was plainly a man of peace.

This was Billy Martin?

In a word, yes. He may look strange suited in green and gold, but then what could be stranger than Martin managing the Oakland A's?

It the pairing of Charlie Finley, the A's controversial owner, and Martin, the quintessentially controversial manager, was inevitable, then so must be their parting. Finally has run through 18 managers in 20 years; Martin has been fired five times in the last 11 years. Together, they should be about as stable as the gold market.

Their histories are well known; their pasts have sometimes intertwined.

But to those A's on the field, those often stumbling A's, Martin means something beyond brawling. He represents legitimacy and, perhaps, a lifeline. s

It appeared before Finley hired Martin (recently fired for the second time by the Yankees) that he had given up on the A's, allowing them to slip from dynasty to despair. They're a laughing stock, a team almost no one in Oakland come to see. The only times Finley makes news these days is to fire or hire a manager or to fuel talk of selling the franchise.

"With Billy here," said Dave Heaverlo, an A's relief pitcher, "maybe we're heading back into the major leagues."

That's what the players hope. That under Martin, things will somehow be different. That under Martin, the A's might win more than 54 games. That under Martin, the game will be played in approximately the way it was designed.

Said Mitchell Page: "Billy Martin could mean 15 to 25 more wins, just by himself.

That may be optimistic, but the A's, who have had little reason for optimism for some time, have several years quota stored up.

"When a team gets beaten down," pitcher Rick Langford said, "you tend to get complacent. Martin will shake this team up, even if it's to get someone mad. We need to get out of the old dull routine: win one, lose a few.

"Martin has always been a winner. Some of it is bound to rub off on us."

It's evident the A's players think highly of their new manager, most of them citing Martin's reputation as one who sticks up for his players.

But can Martin be happy with the A's? And why is he managing this team of rejects, anyway?

"I wanted a job," said Martin, who loses jobs because he can't get along with owners or because he gets into fights. "I could have waited for a better one, but I'd go crazy waiting. I love baseball. I really can't stand to be away."

With the A's, both his love and patience are being tested. His strategy is to rebuild the club starting with the barest fundamentals.

And, on this day, Martin predicted that his Oakland A's, losers of 108 games last year when they finished 34 games behind the Angels in the Al West would this year win the division.

"The Angels are the team to beat," Martin said, "and we're going to do it.

"We've got good pitching and if our defense is as solid as we think it is. . ."

"The pitchers had to get four, five and six outs an inning and you just can't survive that way," Martin said. "The talent is here and now these guys are just learning how to play, how to execute. We're teaching them things they've never been taught before. In one inning against San Diego the other day we had a hit and run, squeeze and stolen base. We really opened some eyes."

Martin smiled and said, "People thought I was crazy when I took over a Texas team (1974) that had lost 105 games the year before and predicted it could win the division. We didn't win, but we did finish second, only four games behind the A's. I know what I'm talking about.

"The players are all excited. That's half the battle right there."

Battling, of course, is not unknown to Martin. He was a battler when he played, a scrappy second baseman who, in 1953, was World Series star. He's been in more than his share of fights, but he says, at age 51, that part of his life is behind him.

Yet, like the aging gunslinger, Martin won't be left alone. He told the New York Times:

"The day I checked into our hotel here a guy held up his hands and said. 'Don't hit me now.' I get that everywhere I go. I bet 30 people have done that. 'Don't hit me now.' Like I'm going around slugging people. But some guys are hoping I will.

"One night in New Jersey four different guys in four different places tried to goad me. I finally had to go home, it must have been a full moon."

Martin paints himself an innocent man, hounded by those who would see him fall.

"What am I supposed to do, walk away?" he wondered. "I tried not to embarrass the marshmallow man by saying he slipped. Lasorda gets into a fight, and what happens to him? Nothing.

"Maybe I need to wear a sign: 'Leave me alone.' Or maybe I should go around wearing a cast on my arm, a patch on one eye and walk with a limp."

It probably wouldn't do any good. Martin is too easily recognized even now behind shaded glasses and dressed up like an Oakland A. He signed a two-year contract for a reported $250,000 to manage the team. Probably no Oakland player makes as much.

Some speculate Martin was hired only to increase the value of the franchise, which Finley may or may not sell, depending upon which story you read. For sure, Martin is the only manager in baseball who will draw fans into a ballpark simply by his presence.

"We can draw in Oakland," said Martin, who grew up in nearby Berkeley. "We'll have a good, young, hustling team. They only had 8,000 for their opener last year. This year, I bet they have 35,000."