Umpire Mechanics an animated DVD Preview. The Amateur Softball Association of America (ASA), The National Governing Body of Softball, is proud to introduce this ASA Umpire Mechanics DVD aimed at all levels of ability. This DVD Covers Plate Mechanics including Stance, Set Position, The Pitch Movement, Plays at the Plate and Base Mechanics Including Starting position, Tag Plays, Force Plays, Plays at 1B, Inside/Outside Theory, Adjustment from Primary Position, Fly Ball Coverage, Between Innings Mechanics.