there is a one size fits all designation for how this gets handled. Obviously some kids want to play and you tell them you do not see a path to field they take the hint to leave. Also, some kids take their own initiative to leave for same desire to play. Some kids end up not being able to play due to some "physical condition" and come off the list due to medical scholarship. The remaining methods are less savory and involve different type pressures. One thing holds true, the numbers always work out.