For the Philadelphia Phillies, it's always the same. When the pressure comes, they turn to stone, petrified by an excess of nervous energy, a flood of adreneline and a consuming desire to please their fans, silence their critics, and, above all, prove themselves worthy.

So, when Mike Schmidt woke up today in Canada and felt awful -- sick as a dog, with flu and plenty of fever -- he said to himself, "Probably just what I need. I'm so miserable I feel as limp as a rag doll."

Schmidt has spent his baseball life trying to find a way to achieve relaxation -- that sense of almost limp calm -- under the greatest pressure. He has tried meditation and born-again religion. He has tried being totally cool and he has tried being enthusiastic.

But tonight he discovered the flu, and it may have transformed the Phillies' season. If not for Schmidt's sacrifice fly and his game-winning 47th home run, the Phillies might have gone down to an ignominious 1-0 defeat tonight to the Montreal Expos, instead of clawing their way to a 2-1 victory that gave them undisputed possession of first place, by one game, over the Expos in the NL East.

Of all Phillies, Schmidt is the most appropriate symbol for this team -- talented, outwardly blase, a target for every boobird and inwardly wound as tight as a Superball. And, thus far in his career, dogged by a reputation for failure on the game's most dramatic October stages.

Tonight's results, stated simply, sound elementary. Schmidt gave winner Dick Ruthven a 1-0 lead with a fly ball to right field in the first inning after Pete Rose had singled and Bake McBride had doubled. And, in the sixth, he smoked a low fast ball from starter and loser Scott Sanderson over the left field fence in the corner for a 2-0 Philadelphia lead and the eventual game-winning run. That frozen rope gave Schmidt, the majors' homer leader, a share of a big-league record -- most home runs by a third baseman, tying him with Eddie Matthews, who had 47 in '57.

But nothing is simple for Schmidt. He doesn't have the blessing of being able to rely on one-dimensional emotion, like Tug McGraw, the left handed Philadelphia buzz saw who saved the victory by getting the last six Expo outs, five of them on strikeouts.

To McGraw, baseball is just a glorious, thigh-slapping, gut-busting game. Ask him how he got up for this big game, and he says, "I took three Tylenols instead of two. They're easy to get across the border."

By contrast, Schmidt, who may be the most valuable player in baseball right now, has to analyze everything to dust. He'd make a wonderful Expo at the moment. The Montrealers have to figure out a way to beat the Phillies back-to-back in the last two games of this season to wrench first place back from the interlopers. After their Steve Rogers meets mediocre Larry Christenson Saturday, the Canadians must send rookie Tim Gullickson against 24-game winner Steve Carlton Sunday. This evening, however, Schmidt was too ill to think overmuch. "You know me, he said, clenching his fist and bicep into a knot. "Can't get loose (cough . . . cough). But all day I felt totally blah. I told myself, 'Just make contact tonight.' Of course, that's what I always tell my damn self, but I don't always do it. When I do, I make out like a bandit (cough . . . hack).

"I didn't take my temperature. I didn't want to know. I figure it's about 111 1/2 degrees. I won't take antibiotics because it makes you lightheaded and you can't see the pitch (hack . . . wheeze).

"Besides," he said mischievously, "with all the drug probes around here this season, you never know when somebody may hand you a bottle and ask for a sample."

In the biggest games, the best players come forward. And Schmidt, at the moment, is coming forward. In the past two seasons, he has hit 92 homers and driven in 232 runs. He has fulfilled every bit of the vast potential always predicted for him -- slugging, drawing walks and playing Gold Glove third as he did with two outstanding plays tonight. But, because he is an old story, well-known, a misjudged personality, few baseball followers realize that, after moving well off the plate last season, he is a totally transformed player. And a better player than ever before.

"I'm a different player," Schmidt admits. "Just a couple of years ago, when Sanderson quick-pitched me in the first, I might have gotten mad. When he threw me a fast ball on the outside corner with two strikes, I might have tried to pull it and struck out. What a downer. With men at second and third and none out, you've got to get somebody home. And if I hadn't, it might have messed up my flow for the whole game. Then the home run in the sixth never would have happened."

It is Schmidt's curse that he knows himself this well. He's a natural with the mind of an always-experimenting hypertense scrapper. But now, at last, he is ready to unveil the finished product -- the ultimate Mike Schmidt, who may be the best combination slugging-fielding third baseman in history. That is, if he only had a stage.

"It's true that my last two seasons have gone largely unnoticed," he acknowledged. "That has everything to do with the World Series -- whether you're in it, and being talked about, or whether you're sitting home. Most people don't remember much about baseball except what happened in that two weeks in October." And Schmidt's October average for three playoff series is .182.

If the Phils can win one of their last two here, Schmidt, who has hit eight homers in the last 14 games, may have his stage. He never will have the charm of McGraw, who, commenting on the Phils internecine squabbling this week between Manager Dallas Green and Larry Bowa, said tonight, "We flush our minds in public for exercise."

Schmidt only empties the well of his mind in private.In the Phillies' clubhouse, he sought out and congratulated old reliever Sparky Lyle, who got five valuable outs in the sixth and seventh innings between winner Ruthven (17-10) and saver McGraw (20). On a team that supposedly has no team spirit, Schmidt knew who had been overlooked.

Between coughs and sneezes, Schmidt was grabbed by a television crew. "We're on live back to Philly," Schmidt was told.

"Aw, Jeez," muttered Schmidt. "It never stops." Then he brightened. "My kids are watching," he said. The camera light went on. Dour, serious Mike Schmidt looked into the lens, squiggled his face up like a clown and waved to the only people in Philadelphia whose approval he cares about.

"Daddy went deep," he said, "cough . . . cough."