A System of Control defines the type(s) and number(s) of referees assigned to a specific game.

Each system of control has:

Each position defines a unique skill set or ability level, a set of game fees, and a name. The ranking determines the order in which the referee positions are shown in the system. The ranking also determines the order in which the positions are assigned, when running the auto-assign process.

In soccer, up to four officials are assigned to a game: a referee, two assistant referees, and a fourth official. The two assistant referee positions are interchangeable. As a result, there are three positions defined: referee, assistant referee, and 4th official. This system of control is defined by one referee, two assistant referees, and one fourth official, for a total of four referees.

In College mens basketball, there are three officials: a referee, and two umpires. Their responsibilities are nearly identical, however, the assignor may want to specify in advance which official is to assume the responsibilities of referee. For this example, there are two positions: (referee and umpire), and the system of control is defined by one referee and two umpires.

In High School baseball, an assignor uses three umpires to cover a game. Each umpire is paid the same, and the decision of which person will work behind home plate is made by the officials on the field. In this example, there is only one defined position (umpire) and system of control is defined by three umpires.

In College football, seven officials are used, each with a unique position name (referee, umpire, head linesman, line judge, back judge, side judge, field judge). In this example, the system of control is defined by seven officials, with each being a unique position.