INDIANAPOLIS, AUG. 12 -- Ron Fraser, coach of the U.S. baseball team, issues a warning before you come and see his team play: "You're going to sit there and think, 'What in the world is this guy doing? He must be nuts to make them play this way.' But let me tell you, that's the way we're gonna play."

Sure enough, through three games here at the Pan American Games, Fraser has been true to his word. In the very first inning of the very first game, two of his aggressive base runners got thrown out by Canada.

And today, after scoring 10 runs in the first inning against Nicaragua, the United States finally ran itself out of the inning when a runner was thrown out at the plate during a double-steal attempt. Even in the sixth, with an 18-run lead, Dave Silvestri tried to stretch a triple into an inside-the-park homer when the relay man held onto the ball for an extra second.

He was thrown out, but it hardly mattered as the U.S. scored an 18-0 victory over Nicaragua in a seven-inning game, mercifully shortened by the 10-run rule.

"We don't have any mashers on this team, just rabbits," Fraser said. When someone asked the coach if he would compare his team to the slap-and-steal St. Louis Cardinals, he said, "Hell, no, we're a lot riskier than that."

The U.S., now 3-0 in the seven-game round-robin portion of the tournament, is an underdog overall. Cuba, Canada and Puerto Rico are supposed to be the top teams in the Games, which poses a problem for the U.S. since it probably needs to finish in the top three here to qualify for the 1988 Summer Olympics.

The U.S. figured to be playing with some pressure today, considering the headlines created by the politics of the matchup. And while Fraser hasn't disguised the importance of doing well ("Coach Fraser says we'll be banned from baseball for the rest of our lives if we don't win here," winning pitcher Jim Abbott of Michigan said today), everybody on the home team seemed to be loose. It sent 14 men to the plate in the first inning and collected 10 runs and 10 hits off two Nicaraguan pitchers.

So much for attaching political significance to a sporting event.

Tino Martinez, the stylish U.S. first baseman, had five RBI on a three-run homer and a two-run double in the big inning. Barney Boltodano, the Nicaraguan starter, couldn't retire a single American hitter and was relieved after five consecutive hits.

Abbott, who was born without a right hand and receives tremendous support from the fans everytime he pitches, struggled with his control but allowed only one solid hit in five innings with a crowd of about 7,000 watching. It was the first victory in the competition for Abbott, who deftly switches his glove from his right arm to his left hand after releasing the ball.

Fraser feels he has a choice with this team: gamble or lose. In 1973, the U.S. won its only world championship when Fraser picked a team of 20 left-handers. "Purely a gimmick," he said recently.

One significant disadvantage the United States has in international baseball competition is the age of its players: It has 19-year-old kids playing against some teams with major league-caliber veterans. "I have to get special permission from the parents of my guys to play night games, they're so young," Fraser joked.

Eleven of Fraser's players are college sophomores. So, besides pulling double steals with nobody out and bunt-and-run plays with two strikes, he does not allow any of his pitchers to work more than five innings per game.

Suppose someone has retired 15 straight and he's got a no-hitter? "He's coming out," Fraser said. "Maybe he'll go an extra inning. Maybe." He cares nothing about using four pitchers in a game, even though there are only seven on the roster.

"Look, I know I'll get some criticism because what I'm doing is not baseball tradition," Fraser said. "The reason I wanted to do something different with our pitching is that I looked at the guys and I didn't think we had anybody who could go nine innings against Puerto Rico or Cuba.

"The U.S. doesn't win in international baseball, so we got to do something different, right? Maybe I'm not real bright for doing it this way. But the other guys before me weren't real bright either. We may blow ourselves out of an inning, double stealing or something, but we have to play this way.

"Do I play the percentages? Hell, no. I roll 'em. That's why people come to watch us and say, 'This guy's a nut case.' "

Fraser picked a team suited to his strategy. He didn't invite many sluggers to the tryouts. "Give me some guys who can make contact and run a little bit," Fraser said.

Through 34 exhibition games -- including five each against Cuba and Canada -- and three Pan Am games, there have been very few strikeouts by U.S. hitters. Outfielder Don Guillot stole 20 bases in 24 attempts on the tour after setting an NCAA record last season by stealing 107 bases in 58 games with Pan American University.

Fraser is becoming convinced that the best way to beat Cuba -- Saturday's opponent and the favorite to win the Pan Am gold medal -- is to try the unexpected. "Nobody aggressively goes after these guys," he said.

That's not to suggest that the U.S. team is a bunch of hitless wonders. It had it easy against Venezuela and Nicaragua after beating a good Canadian team. But Ty Griffin, Georgia Tech's sophomore second baseman, Martinez, a Division II star at the University of Tampa, and University of New Orleans outfielder Ted Wood have shown power. And 12 of the players, including Abbott, have been drafted by major league clubs.

Fraser is just happy to be here, let alone have a team that's undefeated. A week ago today, Fraser, renowned for his success as the head coach at the University of Miami, had to check into a Dayton, Ohio, hospital because of pain caused by kidney stones.

"Right now, I feel pretty good," Fraser said. "I'm hoping I can get through the games. But I'm carrying around my X-rays with me in case anything happens."