Diamond comedy

IT sounds like a parody on Abbott and Costello's classic baseball comedy routine. But instead of ''Who's on first, What's on second,'' it now is: What's in the dugout, who's in the clubhouse?

What's in the dugout is a computer. In the New York Mets dugout. Manager Dave Johnson, a college math major, figured an electronic coach would do better than a human one at making sense of baseball's statistics.

How skillfully the computer's playing its game we don't know, but the Mets are doing fairly well at theirs: They're now in third place.

While the computer's in one team's dugout, Sam Morris is in another team's clubhouse. Sam's a junior high school student and the batboy of the Portland Beavers of the Pacific Coast League. Seems one of his team's coaches was provoked enough during a recent game to hurl a folding chair onto the playing field. The umpire told Sam to retrieve it, but his teammates said no and he obeyed them, since he works for the team.

Alas. Umpires are like parents. They have the last word. This one ejected Sam from the game and banished him to the clubhouse.

In the Abbott and Costello routine, if memory serves, ''Who'' played first base, ''What'' was the second baseman, and ''I-don't-know'' was the shortstop.

In today's crazy-quilt game of baseball, Who knows What comes next?

I-don't-know.