Without fielders knowing who has the fielding priority to call the other player off, one of two events can happen: 1) a collision between two determined and aggressive players, or 2) the ball dropping between two overcautious and timid players. In either of these situations, a routine fly ball can turn into a costly game changing play. The solution to this dilemma is setting up a system covering all fly balls and pop-ups. The two fielders involved immediately know who has prime responsibility, whose call takes precedence, and who should back away. More...