FORGET ABOUT mandatory drug testing, player contracts and whether Washington is going to get a team. The most vexing question in baseball the past week, according to Billy Martin and George Steinbrenner, is the unacceptable state of one stadium: the Hubert H. Humphrey Metrodome in Minneapolis. Mr. Martin, who at this writing was manager of the New York Yankees, took the unusual action of protesting a game before it had even started Wednesday (the protest was later disallowed), on the grounds that the lights in the domed stadium cause his outfielders to lose track of fly balls. He was backed up by the Yankees' owner, Mr. Steinbrenner, who said: "What takes place in the Metrodome is not a ballgame, it is a circus."

With due respect to Yankee management, it is not a circus either. As anyone can tell you who has watched games played in the Metrodome, it is something more on the order of Electric Ping-Pong and Moon Golf, with 31/4 innings of baseball laced through it. What this game should rightly be called is Hubert H. Humphreyball, because it is the spirit of the man for whom the dome was named that dominates there.

It is a place that has more than just those funny lights that make fly balls an adventure. It has walls close enough that the tiniest batter can aspire to a home run, a scoreboard that leads cheers, a din of old rock music, plastic sheeting on the high fences that billows like a waterbed when batted balls hit it, great tunnels emerging from under the stands that look like storm outlets for a TVA project, and, beneath it all, artificial turf of a corky resiliency that keeps pitchers in agony. Bouncing ground balls gain height on each successive hop (boing, boing, BOING), and line-drive singles take great bounding leaps as visiting outfielders scramble in confusion, children shriek happily, runners circle the bases and numbers mount on the scoreboard.

When the Minnesota Twins have a good team, as they appear to this year, the dome is in constant turmoil. "Would Hubert H. Humphrey enjoy the Hubert H. Humphrey Metrodome?" asked a baseball writer for the Baltimore Sun. He knows the answer as well as we do.

At times, we'd like to think, certain more attuned fans may hear an ethereal voice coming over the loudspeakers: "Now by gosh, didn't I tell you there isn't a better place on earth than right here in this great Metrodome of ours, where even the lowliest batted ball can aspire to be a home run if it just hops high enough on that last bounce, with some outfielder standing out there looking gloomy as Calvin Coolidge while he's waiting for it to come down. And just to think some people said you can't play baseball in a pinball machine. Well by golly I wish they could be here tonight to see all these happy faces and hear the umpire shout 'Play ball,' with everybody going . . ."

Boing, boing, BOING, BOING, Whee!