From swimming in lanes to jogging in parks, early-morning workouts tend to be solitary. Not at the Embarcadero Y.M.C.A., where full-court five-on-five pickup basketball games start at 6 on Mondays, Wednesdays, and Fridays. Long waits to play are rare, and the competition is largely good-natured. You won't find Monta Ellis gliding through the lane here, or even Andris Biedrins rising up for a rebound. The usual parade of shirted and skinned gym rats holding court here include foul-prone scrappers, lumbering screen-setters, and cagey old dudes clinging to a few ankle-twisting spin moves. Beyond calories burned and tensions released, the only rewards are bruises and postgame nibbles at the Ferry Building.