ATHENS, Greece -- The 50-meter freestyle race is one length of the pool. No round trip. No push off the wall. No dolphin kicks underwater.

Fastest swimmer wins.

An illustrious group will gather today at the Olympic Aquatic Centre for the opening rounds of the 50. One will be the defending gold medalist, another the world record-holder.

Ricky Busquets, a Ross resident who competes for his native Puerto Rico, is determined to dent the field but knows it will be a great challenge.

As he put it, "I have to run my best race."

That will take some doing.

For one, Busquets, 29, is fairly well removed from his greatest successes.

He is deeply experienced, appearing in his fourth Olympics and having reached the final of the 50 and 100 in each of the past two. He has won the World Cup three times and twice finished among the top three in the World Championships. But the last of his medals came in 1998, when he tied for bronze in the 50 at the World Championships.

It also will not help that the elite swimmers against whom he has competed over most of those years remain at or near the top of the world rankings on merit.

Included in the group that has preliminary and semifinal heats today are:

Gary Hall Jr., 29, is the greatest sprinter in United States history and was the Olympic champion in Sydney. He has eight Olympic medals in his career and remains rated No. 1 by FINA, the international governing body of swimming.

Alexander Popov, 32, set the world record in the 50 in June 2000 with a time of 21.64 seconds. He won the World Championships last year.

Jason Lezak, 28, is not far behind his U.S. teammate Hall. In the past year, he has won the 50 at four major events.

Jeff Berghoff, head coach of Team Pittsburgh Aquatics, of which Busquets is a member, expressed confidence that Busquets can keep pace.

"For the 50, you need to be very powerful in the water, have great explosiveness and quick reaction time," Berghoff said. "Ricky's reaction time is phenomenal, as is his kick."

Busquets, born in San Juan, Puerto Rico, is studying dentistry at the University of Pittsburgh. He and his wife, Emily, are planning to make the region their home.

The final of the 50 is tomorrow afternoon, Pittsburgh time.