United States Olympic Trials (track and field) fill out the field. Since 1972 there have been a minimum of 24 entries in any event, with the popular sprint events 100 meters, 200 meters, 400 meters and 110 meter hurdles having a minimum of 32 entries. Since 1992, athletes achieving the "A" standard are funded to attend the Olympic Trials, while "B" standard athletes have to pay their own way to the meet. Unlike many other countries, who have a selection committee, the selection to the United States Olympic Team is exclusively by results on the track. It's "do or die" in the prescribed event. If two or
All-weather running track today. In the mid-1960s Tartan tracks, surfaced with a product by 3M. The name "Tartan" is a trademark, but many have misused it as a genericized trademark. This process was the first to commercialize a polyurethane surface for running tracks, though originally conceived for horse racing. Many Tartan tracks were installed worldwide, including at many of the top Universities in the United States. Among that list was a Tartan track installed in the Estadio Olímpico Universitario, home of the 1968 Summer Olympics at Mexico City, which were the first global championships to use such a track. Olympic shot put champion