The time has arrived when the burden of proof concerning the Baltimore Orioles has finally shifted.

After two seasons of sputtering play, the Orioles must now be considered guilty until proven innocent.

Guilty of what?

Guilty of being merely good, not excellent.

The Orioles' sentence is to be imprisoned in third place -- give or take a spot in the standings -- for an indefinite period of time.

For years, the sensible assumption about the Orioles was that they were great, or, at least, exceptional, until proven otherwise. After all, they won more games than any other team in baseball in the '60s, again in the '70s and then started the '80s with 100 victories. That's a tradition.

Now, the juncture seems to be at hand when the proper presupposition about the Orioles is that they're merely a pretty good ball club. That is, until such time as they once again demonstrate themselves to be a club of the first rank.

When a team follows a .562 season with a 60-54 (.526) start, that's sufficient evidence to conclude that, while these guys may be more than competent, they're not much of a threat to win a pennant. The last such lull in Orioles history came in 1975-76 (.566, .543), when a team that had won five of six division titles had to be rebuilt on the fly into the young '77-to-'80 gang that often reached inspirational levels of play.

Eventually, the 1981-82 seasons may well resemble those back-to-back second-place finishes in 1975-76.

The irony of all this is that, ever since the advent of free agency in 1976, modestly endowed Baltimore has -- on paper -- appeared to be just such a competent but basically limited team. However, on the field, the Orioles had an eminent camaraderie, an offensive chemistry and pitching so sound that it took them far above their individual skills and made them one of the game's very best teams.

Now, the team seems to have arrived at the place where cold-blooded analysts -- cynical scoffers at "Oriole magic" -- thought they should have been all along.

If the Baltimore organization has an encouraging hallmark it's that the bad times are hard to distinguish from the best of times.

And, make no mistake, by Baltimore high standards, these are bad times.

The Orioles are sixth in the American League in runs scored and ninth in ERA with a mark just over 4.00. They've outscored their opponents by a mere 34 runs -- the surest mark of a going-nowhere team. Considering these numbers, the Orioles are blessed indeed to be "just" seven games behind Milwaukee as they enter six consecutive series against Minnesota, Texas and Toronto, who, collectively, are 63 games under .500.

The Orioles' 33 steals in 114 games is, by modern measurement, awful. The team's defensive range runs the gamut from adequate to nonexistent. Only catcher Rick Dempsey and first baseman Eddie Murray are defensive pluses; all others struggle for respectability. On AstroTurf, the Orioles look as anachronistic as if they were wearing baggy flannels and pancake gloves.

When owner Edward Bennett Williams arrived here for what Earl Weaver called "a state of the club" talk to the team Saturday, he could not have been in a cheerful mood.

Except for John Lowenstein (.319), Gary Roenicke (18 homers), Jim Palmer (9-3) and Tippy Martinez (7-6, 11 saves), it's hard to find an Oriole who is having a better-than-average season.

Those far below proven form are easy to find.

At 6-foot-7 and 250-pounds, reliever Tim Stoddard might be the world's largest kerosene can. His problem, aside from always looking lethargic, is fairly simple: he's a fast ball pitcher who can't find his fast ball.

On arrival in Baltimore, Dan Ford's career batting average was .276. Now, his on-base percentage is .276. That Doug DeCinces should have 24 homers and 73 RBI only makes Ford's eight homers and 37 RBI more painful.

The day is imminent when Ken Singleton will no longer be allowed to drag his .183 batting average, his .225 slugging percentage and his .315 on-base percentage to the right side of the batter's box. Still a decent lefty hitter, Singleton's right hand is weak, sometimes numb, and needs a complete winter's rehabilitation. It says here that he'll come back well in '83. But, for the rest of '82, he should be platooned at DH with Benny Ayala. Maybe he should have been two months ago.

The list of more minor culprits goes on and on. Al Bumbry, hitting better lately, looks old. Eddie Murray's .313 average is soft because he's constantly pitched around with men on base.

Often overlooked is Baltimore's severe coaching drain in recent years. No team could adequately replace such genuine instructors as George Bamberger, Billy Hunter, Frank Robinson and Jim Frey; and the Orioles certainly haven't.

Despite all this, the team's true soft spot is, paradoxically, the area that would seem potentially to be strongest -- the young-veteran pitching trio of Scott McGregor, Dennis Martinez and Mike Flanagan. Their combined record is 31-31 with an ERA of 4.12; that's an accurate reflection of their mediocre performance this year. All are, and have been, healthy. The defense behind them, if slow, is still second in the league in fielding percentage. And the offense, if unspectacular, should be more than adequate for quality pitchers.

How could the Orioles bring their division race to a boil?

Simple.

If McGregor, Martinez and Flanagan pitch like they have the previous three years--46-19, 35-25 and 48-28 -- then, in a sport that currently has no team playing .590, the Orioles could still cause palpitations.

The burden of proof, however, has now swung to the Orioles.