Ever since they got into the business four years ago of combining forces and beating up on others, Doug Ganim and Dan Obremski have had this fear that one day they might run into another pair that is, heaven forbid, just like they are.

The names Ganim-Obremski may not mean much to you; they may not give you indigestion or keep you up nights. You've probably never thought of buying dolls that look like these guys and sticking pins in them. But the best racquetball players in the world entertain such thoughts. And they have been since the 1986 National Doubles Racquetball Championships in Jacksonville, Fla.

On that occasion, Ganim and Obremski came waltzing into the nationals as a doubles team nobody outside of Ohio and Pennsylvania (where they're from) had ever heard of. They'd been a team for all of three weeks. They were unknown and unseeded.

They proceeded to move through the Florida draw like a tropical storm. The seeds fell fast and hard. As the field yelled "hindrance," Ganim-Obremski won the national title from the far rail.

They'd never won any national singles titles on their own (and still haven't), but as a team they proved to be just about unbeatable. They repeated as U.S. champions at the nationals in Arizona in 1987, won their first world championship in Germany in 1988, won another U.S. national title in 1989, and another world title, 1990 vintage, in Caracas, Venezuela, just this past August.

Since they're the best in the world as well as the defending national champion, it's no suprise the Ganim-Obremski entry is seeded No. 1 in the 1990 Ektelon U.S. National Doubles Championships that opened yesterday at the Sports Mall and will run through Sunday. It's no great shock to anyone that when Dan and Doug walk into the locker room it gets rather quiet. Any other team wants the title, it's gotta go through them.

But that doesn't mean Ganim and Obremski can't worry that what happened to the seeded teams five nationals ago can't happen to them.

"Especially this year," says Obremski. "All the solid doubles teams have split up. There are all kinds of new teams. We came in that way in '86. With new teams, you don't know what to expect."

For example, Egan Inoue, the Hawaiian who is ranked No. 1 in professional singles, has found a new partner in Brian Hawkes, who is ranked in the top 12. That's a formidable new pairing - seeded No. 2 this week on the strength of the team's singles accomplishments.

Obremski is ranked in the top eight in singles, and Ganim in the top 18. On paper they should lose to Inoue-Hawkes, and a few others.

"Through the years our chemistry has made the difference for us," says Obremski. "If one or the other of us is playing bad, we still have develped a knack of winning. We're able to cover the court.

"But we know we've got to dive and kill ourselves to win. A lot of teams scare us."

Not nearly as much as they scare them.

Ganim and Obremski seized on the idea of a merger back in the summer of '86 when it dawned on them that since they kept facing each other in the finals of singles events at professional tournaments in Ohio (where Ganim is from) and Pennsylvania (where Obremski is from), they ought to join forces in doubles, where they both could win.

They played in three pro tournaments before the 1986 nationals, won all three, and then won that first U.S. title - and the best pair of racquetball players in the world was born and thriving.

Four years later, and Ganim and Obremski still live in their separate states, Ohio and Pennsylvania.

"We don't need to live in the same city," says Ganim. "We always get together on weekends anyway."You can tell them apart if you catch the matches this week at the Sports Mall. Dan is the one taking most of the forehands, and Doug most of the backhands. They've found that strategy to work the best.

When they return to playing singles, they have to adjust back to all-around games, using both forehands and backhands. "That's the only drawback of playing doubles," says Obremski.

When you consider the stranglehold they have on tag-team racquetball, that's really no drawback at all. Ganim and Obremski. The whole is greater than the sum of the parts. Together on a racquetball court they have nothing to fear but themselves - or somebody just like them.