Umpiring
Decisions about play are made by umpires. They make the decisions like a referee in football. The number of umpires on a given game can range from a minimum of one to a maximum of seven. There is never more than one "plate umpire"; there can be up to three "base umpires", and up to a further three umpires positioned in the outfield. Most fast pitch games use a crew of two umpires (one plate umpire, one base umpire).
Official umpires are often nicknamed "blue", because of their uniforms – in many jurisdictions, most significantly ISF games, umpires wear navy blue slacks, a light powder blue shirt, and a navy baseball cap. Some umpires wear a variant of the uniform: umpires from the United States Slo-Pitch Softball Association (USSSA), for example, wear red shirts with black shorts. Canadian umpires can wear either a light blue or red shirt. Regardless of what uniform is worn, all umpires in the same game are required to have matching clothing. Decisions are usually indicated by both the use of hand signals, and by vocalizing the call. Safe calls are made by signaling with flat hands facing down moving away from each other, and a verbal call of "safe". Out calls are made by raising the right hand in a clenched fist, with a verbal call of "out". Strikes are called by the plate umpire, who uses the same motion as the out call with a verbal call of "strike". Balls are only called verbally, with no hand gesture. The umpire also has the option of not saying anything on a ball. It is understood that when he stands up, the pitch was not a strike. Foul balls are called by extending both arms up in the air with a verbal call of "foul ball", while fair balls are indicated only by pointing towards fair territory with no verbal call. All decisions made by the umpire(s) are considered to be final. Only decisions where a rule might have been misinterpreted are considered to be protestable. At some tournaments there might be a rules interpreter or Tournament Chief Umpire (TCU) available to pass judgment on such protests, but it is usually up to the league or association involved to decide if the protest would be upheld. Protests are never allowed on what are considered "judgment calls" – balls, strikes, safes, fair/foul and outs.

