Assertion: arbitrator | /r/AtLocation | different positions
Facets:
value: as the play demands
type: MANNER
value: on the field
type: LOCATION
Source sentences:
text: When three umpires are used, the second umpire is called the first-base umpire and the third umpire is called the third-base umpire, even though they may move to different positions on the field as the play demands.