Assertion: table tennis's umpire | /r/HasProperty | sure
Facets:
value: by requiring the server
type: MANNER
Source sentences:
text: Also, by requiring the server to throw the ball upwards within a few degrees of the vertical (rather than a previous rule which stated it had to be within an angle of 45°), the umpire can be sure that the ball has been thrown upwards and not sideways or diagonally.
text: This means it must rise within a few degrees of the vertical, rather than within the angle of 45° that was formerly specified, and that it must rise far enough for the umpire to be sure that it is thrown upwards and not sideways or diagonally.
text: If the umpire is sure the serve is a fault, he is supposed to call a fault straight away.
text: The umpire has the right to overrule a line judge or a net judge if the umpire is sure that a clear mistake has been made.