Baltimore's talk of the town is Gregg Olson, the Orioles' right-hander who has been reducing hitters to muttering victims of the stuff that comes out of his pitching fist. Seldom has a relief pitcher been such a dominant figure, and around the rest of the league this is being agreed, if grudgingly.

Olson and his 6 feet 4 inches have been such a presence on the pitching mound that his every emergence from the bullpen brings expectation of more heroics. His effectiveness can be measured by noting that he has allowed one run, only one, in every 12th or so relief appearance. The two runs he yielded in his 23 games this season have given him a minuscule 0.51 earned run average. Is he a flash in the pan? No. He has a tidy, record-setting 1.23 ERA for his three-year career in the majors.

This, then, is the stuff of which legends are made?

Not quite.

Even if Olson stays the course, goes on to more blue-ribbon years, he must still be regarded as an improbable Hall-of-Famer. He will go into history with an asterisk. This is the badge all relief specialists wear when measured for greatness as pitchers. They are viewed as not quite the whole man by those zealous critics among the game's historians who so often withhold the final acclaim.

Of the 48 pitchers elected to Cooperstown, only one, Hoyt Wilhelm, could be accurately described as a reliever. And Wilhelm's induction was as much a tribute to his longevity, his record 1,070 appearances, as it was through the success of his knuckleball.

The modern relief pitchers are the gunslingers of baseball, engaging in their shootouts when called in to get a threatening situation over quickly. Not until the mid-1920s, when the likes of the Senators' Firpo Marberry made relieving a specialty, were relief men deemed important to the roster. The next noted reliever was probably Johnny Murphy of the Yankees in the late 1930s. Well-remembered is Lefty Gomez's comment when asked how many games he expected to win: "I dunno, ask Murphy."

But in the 1960s that tribe began to increase. And now managers speak of relief men as short relief men, long relief, middle relief and closers, inclusive new additions to the language of baseball, which once described pitchers as pitchers.

The complete game is now a rarity bordering on a surprise. Managers speak now of "a fellow who can give us five or six good innings," which is supposed to be a compliment.

Also, relief pitchers have more going for them than starting pitchers. In most cases they come into the game as strangers to the guy at bat, who may not have seen their stuff before, or only a few times at best, lack intelligence about their stuff, and are under a handicap. What an edge for any pitcher.

And some of their fancy earned run averages won't bear scrutiny, can be debunked, Gregg Olson excepted. They come into a situation with runners on base, absolved of discredit if any or all of them score, and have the advantage of easy outs on force plays, or double plays, that is denied other pitchers.

I saw Alvin Crowder of the Senators walk into a game in Boston with the bases full in the eighth and Washington trailing by a run. He threw one pitch and got a double play, ending the inning. In the top of the ninth, Crowder was pinch-hit for. The Senators came up with two runs, won the game, and Crowder was credited as winning pitcher for the one pitch he threw.

The great Walter Johnson often doubled as a relief pitcher, but he couldn't be said to be of the same breed. During his 16-game winning streak in 1912, his second victory came via a relief stint. Johnson was asked to take over in the second inning. He got his victory by pitching shutout ball for the next 12 1/3 innings. He once missed another victory as a reliever after taking over in a 3-3 tie in the seventh inning at Philadelphia. It was still 3-3 when the game was called on account of darkness in the 17th. Today they would call him "a long reliever," which he wouldn't understand.

Olson could be reminded that for relief pitchers it is not an easy road to Cooperstown. Full respect is hard to come by. In 1959, ElRoy Face of the Pirates performed one of the more remarkable feats in pitching history when, without starting a single game, he compiled an amazing 18-1 won-lost record. Off that I thought he deserved Hall of Fame consideration, but he was a reject. It seems that relievers are regarded as somewhat flawed as complete pitching heroes. For all their splendid feats, for all their worshipers, for all their fame, call them semi-demigods.