Baseball is hardball.

For those outside the game, the sport has many a cheerful charm. For kids, it's bubble gum cards and heroes, a mythic realm of bright legends, brave deeds. For oldsters, perhaps it's a nostalgic touchstone. But for those who travel inside baseball's circle and sense its interior life, the bedrock authority of the game may be its uncompromising adult toughness.

To be sure, baseball is Opening Day, the All-Star Game and the World Series. Those glittering festival days are real. But, far more often, the sport is an exasperating six-month test of individual resiliency and team confidence. It's trial by life. Just because a game has foul lines doesn't mean it's fair.

These days, the Baltimore Orioles are being asked to play hardball.

Baseball, if you're an Oriole, is waking up in New York City on a gray rainy Tuesday morning with a rainout in your future (the game will be rescheduled for September) and trying to forget what happened the night before in Yankee Stadium. Forget Benny Ayala dropping a fly and Al Bumbry booting a grounder to throw away a victory. Erase the memory of that vulnerable giant, Tim Stoddard, his self-esteem in tatters, beating himself and knocking his team out of first place in the 11th.

Try not to remember that the team's best pitcher (Mike Flanagan) has been on the disabled list for 40 days and may be there for 40 more. Overlook the fact that the club's right fielder (Dan Ford) and half its catching platoon (Joe Nolan) are also on the DL. Both Ford, who had arthroscopic surgery in Baltimore today (he had no torn cartilage in his knee, but will miss two to three weeks) and Nolan tried to come back too quickly from injuries and did themselves more harm; it's the long season's oldest story. "We've never had this many key injuries," says battered Rich Dauer, who's also "day to day."

If you're an Oriole, you try not to think about the mind games Dennis Martinez (4-11) is playing on himself. "Wish everybody could watch Dennis throw between starts," mutters Ray Miller, the pitching coach. "Great heat on the corners, yackers (curves) off the table. Looks like the best pitcher in the league until he gets in the game. It's gotta be driving him crazy, 'cause it's driving me crazy."

"(Coach) Elrod (Hendricks) comes in from the bullpen after warming Dennis up and he says, 'I'd bet my house Dennis will pitch a shutout.' Then . . . ," says Manager Joe Altobelli with a shrug of the shoulders. "Well, it's a good thing Elrod doesn't bet or he wouldn't have a house."

Martinez, like Stoddard and Sammy Stewart, has always been a bit short on self-confidence; Earl Weaver stroked all three, spoke constantly of their skills and risked using them when others might not. Altobelli has judged them by their performance, not their psyches; they've pitched themselves onto the front porch of his doghouse. The end result is that their pitching poise and weak concentration seem even more eggshell-thin than in the past.

Being an Oriole means trying not to see how many rookies and journeymen are being counted on to win a pennant. John Stefero, Mike Young and Dan Morogiello have played nine games in the majors. John Shelby (three for his last 23) and Leo Hernandez (.246) are weathering the shock of being worked over by big league pitchers with big league minds; one flaw is all they need to start cracking a rookie open. Now the league knows Shelby chases bad balls and Hernandez steps in the bucket.

Two of the team's best starting pitchers are a rookie, Mike Boddicker, and a phenom, Storm Davis, the youngest player in the league. Several veterans--Lenn Sakata, Ayala and Jim Dwyer--are still adjusting to losing a manager (Weaver) who had an inordinate concern for keeping his deep-depth bench sharp with regular work.

Finally, the Orioles try not to watch Aurelio Rodriguez; the gold is gone from his glove and his bat has turned from wood to lead. He's started 11 games in the last month and is "slugging" .135.

If all this sounds like a team in need of cardio-pulmonary resuscitation, it's misleading. Such a combination of injury, inexperience and lost confidence is the rule, not the exception, on almost every team.

The Yankees, for instance, have casualties like Willie Randolph, Rudy May, Ken Griffey and Ron Guidry; they have slumpers like Dave Winfield (.248) and Jerry Mumphrey (.228) and pitching flops like Bob Shirley and Dale Murray.

Everybody agonizes. Everybody doubts himself. Every manager has the chance to panic.

The team that dwells on its hardships falls prey to a fatal self-pity. The club having an almost unshakable belief in its ability to persevere and rebound from calamity usually prevails. It's almost an act of faith.

The Orioles have traditionally been the latter sort of team and show promise of being a survivor again. The Orioles' ability to digest, then forget their most gnawing defeats and injuries, has been an immeasurable asset for years.

Nonetheless, it's hard for a club to remind itself that: Eddie Murray and Cal Ripken are second and third in the league in runs produced; John Lowenstein and Gary Roenicke have combined for 17 homers and 65 RBI in 187 at bats; almost-good-as-new Ken Singleton is back in the league's top 10 in slugging (.505) and on-base percentage (.405); Davis and Boddic-ker may make the staff stronger for years; Scott McGregor's in a groove and Jim Palmer says he's fit.

In fact, when Flanagan and Ford return, the Orioles might well have the best team in the generally weak American League by a clear margin.

Yet the weary Orioles, struggling through a month of vital games within their division, are tempted to feel as their owner does.

"Oh, that was a brutal loss last night," moaned Edward Bennett Williams today on the phone, as though Beelzebub had him by the heels and was dragging him to a warmer place.

In baseball, each (unrainy) day starts with the same challenge, the same burden, the same promise: game tonight. That's why the best team doesn't always win in baseball: the one that quits last usually does. In baseball, as in much of daily experience, the final victories come to adults who endure.