The world champions of Pittsburgh announced themselves here in enemy waters in typical Piratical style tonight. The Bucs might as well have pulled amidships and hollered at the Phillies, "Avast, ye lubbers, prepare for boarding."

The Vet hadn't opened to the public yet at dusk, so the turf belonged to the Phils, taking batting practice, and the early arriving Pirates in black and gold.

The instant Dave Parker, diamond in ear, stepped out of the tunnel and into the Buc dugout, he began bellowing blue insults at the Phils so loudly that every player on both teams had to cock an ear.

"First year in the big leagues and the busher's got something to say," Parker roared at a bunch of Phillies standing innocently behind second base. "Ain't even got a bubble-gum card with his picture on it, but the pig-faced blankety-blank is already runnin' his mouth."

The last time these Pennsylvania foes met, last month in Pittsburgh, matters ended in a bench-clearing brawl after the Phils' Keven Saucier drilled Bert Blyleven. In the aftermath, a Phillie rookie did some brave talking.

"I don't hear Mr. Pig-face talking to me, do I?" Parker asked ino a titanic, echoing bellow in the nearly empty park, his glare directed at the Phils -- rookie in their midst -- 100 feet away.

Players on both teams winked and nudged each other.

"Is this a put-on?" an outsider asked Buc catcher Ed Ott.

"I wouldn't bet on it," Ott replied.

With the Pirates, the question of mood is always moot. What is feigned, what is really felt, is always in doubt. That's how the Pirates want to be: big, loud, dangerous and, above all, a little mysterious.

Moments after his apparent tirade, Parker was chatting and yawning, saying, "Fighting's for Ali and Holmes, not me."

If high spirits, an appetite for battle, and the most masochistic hard-nosed attitude since the Gashouse Gang is the stuff of pennants, then the third-place Pirates have little to fear.

Actually, their midseason mark entering their series here tonight was exactly the same, 43-38, as last season's. The Bucs were even five games behind in fourth place at this juncture in '79.

"We're a stretch-running club, always have been," Parker said this evening. "We're self-confident. We know how to win under pressure. And there's not one of us who won't play hurt if we can be wheeled out there."

At the moment, Parker has pads or bandages on his knee, shoulder and elbow. The highest-paid player in baseball -- $900,000 a year -- is a walking wreck. Why would a star in his prime, with mortal-lock financial security, risk his future, his longevity, his statistical spot in the game's hierarchy, just to beat out a few more double play grounders in July, just to play the second game of double-headers?

"The show must go on," Parker said with a shrug. "Ain't but one right way to play this game. When I'm finished, I want 'em to say about me, 'He played every game like it was his last.'"

That is the Pirates' constant motto.

Tim Foli played with spike wounds so deep that he ended up on the 15-day disabled list after they became infected. Willi Stargell, who has missed 31 games, has insisted on playing with an aggravated hamstring pull until now he too has had to go on the DL to let it heal properly. Parker has just about played through everything.

"On a team of hard-noses, you make certain sacrifices because of team closeness," Parker said. "You just want to do it. Some guys play for the stats, some for the wins."

The contrast between Hank Aaron, who was seldom injured and whose teams -- in his last 15 years -- seldom won, and Frank Robinson, who risked himself constantly and whose teams prospered, was suggested to Parker.

"I'd like to be like Frank . . . spontaneous . . . into the game . . . a leader . . . whatever it takes," Parker said. "I don't care too much about the lifetime numbers."

The question, of course, is whether "Whatever It Takes" is a slogan that can bring results year after year.

"It's so exciting to be part of this team that you find yourself doing all sorts of crazy, risky stuff," said Bill Madlock, whose nickname was Mad Dog for his spikes-up style before he ever came to Pittsburgh.

"Almost everybody has the same attitude: run through the wall. Obviously, the main thing for us is to get everybody healthy so we can make our run," said Madlock, who has the NL's highest career average, but is hitting .241 now because he has refused to rest a series of hand, thumb and wrist injuries gotten by diving and sliding head first on artificial turf.

"But, the way we play, you wonder if we will. Man, Willie has been hurt for months. We've had our lineup intact for only 15 games all year."

The problem with teams that believe in their own "magic," as the Pirates have, is that they also can come to believe that their supply of the stuff has run out. Just ask the Bucs' foe in the World Series -- Baltimore -- which had the dubious inspiration of making its team song a ditty about "Oriole Magic."

After arriving here with their accustomed bravado tonight, the Pirates suffered the indignity of a 5-4 bottom-of-the-ninth defeat to the Phils that was a microcosm of their whole unmagical season to date.

The Bucs matched their ace, Jim Bibby (11-1), against Steve Carlton (14-4) and got the better of the duel. They were leading, 3-2, going to the Phils' eighth, despite Mike Schmidt's 22nd homer.

Surely, the mighty Buc bullpen, the glue of the club, would close the door once more. But it couldn't.

The whole glamor trio -- Grant Jackson, Enrique Romo and Kent Tekulve -- marched to the hill. And all the wrong things happened.

In the eighth, Parker had a whole omelet of eggs on his face after playing Pete Rose's catchable blooper into a two-run, three-base blunder. Parker got a bad jump, got caught on the concrete half-hop and watched in embarrassment as second baseman Phil Garner had to chase the ball all the way to the warning track.

The Bucs started their patented bases-full, none-out magic in the ninth, even kayoing the hated Saucier. But good-luck charm Manny Sanguillen, while tying the score, 4-4, killed the rally, with a double-pay grounder.

Finally, in the Phil's ninth, Manager Chuck Tanner tried a piece of legerdemain, pulling Parker in to create five-man infield with the bases full and one out. Instead of magic, the Bucs got instant defeat as Bob Boone rifled Tekulve's first pitch through the three-man left side of the Pirate inner defense for the game-winner.

To waste a strong start by Bibby, to have Carlton on the hook and let him off, to blow a lead, to botch a rally, then to walk off chagrined as 53,254 people stand and cheer is the frustration of which nightmares are made.

"We hate to lose because you'd be surprised how many people enjoy it," Madlock said, dejectedly. "A lot of fans outside Pittsburgh don't like the way we play or the way we act. They mistake our fun and our confidence for cockiness. They don't know how great these guys are."

Madlock grew quiet. "Matter of fact, I could quit this game right now and be satisfied. In just one year -- last season -- baseball gave me everything it's got to give. I've not only got the ring, but every memory that could go with it.

"We came from behind, we had a great pennant race, we were counted out in the World Series. And then we won it all."

Madlock looked at the tape on his stubby, bruised hands. "Seems like a shame that the glow lasts so short a time," he said.

For the Bucs, the glow is far from gone. But it is definitely in danger of dimming. The Pirates' best break is that no team in the NL East can build a winning streak because no team has a fourth or fifth pitching starter who doesn't send shudders through his teammates.

"Out of Montreal, Philadelphia and us, our starters are the weakest," admitted one Pirate. "But they're good enough to win for us. All they got to do is go five innings, then give the ball to the bullpen."

But this year, strange things have happened in the late innings, just as they did tonight. Through the first six innings of their 1980 games, the Bucs have outscored their opponents, 257-203. But over the seventh, eighth and ninth innings, Pittsburgh has been outscored, 103-70.

Rarely have two teams of greater appeal met in a World Series than the Pirates and Orioles of '79: they were families of diametrically opposite types. Baltimore was, by baseball standards, the gentle, thoughtful group, while the Pirates were the big, courageous, fun-loving family at a communal feast.

Both believed in their magic. Both must question it now.

Pittsburgh, however, is trailing by only 2 1/2 games, by far the more merciful second-half task."We'll have that big winning streak," Tanner vows, remembering the 47-19 Pirate eruption that began last season on July 14.

The Bucs will make their stand with diamonds in their ears, rings on their fingers and their spikes as high as the Jolly Roger on their mast.

"It's just getting to be our time of the year," Dave Parker said, with a marauder's grin.