FOR THE ELITE FEW whom this magazine tends to cover, the American athletic experience is one of teams (Tigers or Phillies) or individual competition (Tiger and Phil). Yet for most of us beyond college age, strictly organized play is a thing of the past, and sport becomes something tribal. We go down to the park for pickup games of soccer, basketball or in-line hockey, or over to the racquetball courts, and very quickly become acquainted with a crew of regulars. Depending on how the sides are chosen, today's teammate will be tomorrow's opponent. But we are still part of the same tribe.