The Championships at Wimbledon is the highest profile event in professional tennis, held at The All England Lawn Tennis Club in London.
According to Wimbledon, 335 tennis officials work The Championships: 275 British officials and 60 international ones.
About 45 officials are assigned to be chair umpires each day at Wimbledon. They sit above the court at one end of the net. According to the International Tennis Federation, their duties include ensuring that players and officials observe all of the game rules. They also track the score; make sure that spectators don't interfere with play; verify or overrule calls made by other officials; and decide when to stop play because of an injury, inclement weather or darkness.
Line umpires watch the baseline, sideline, service line and centre service lines, making "out" and "fault" calls for those lines.
The net umpire sits at the net post, opposite the chair umpire. The net umpire makes "net" and "through" calls, along with making net measurements when necessary.
Ball Boys and Girls
About 250 boys and girls work The Championships at Wimbledon. They arrive about 10:30 a.m. each day and work in teams of six -- one hour on, one hour off -- until the last court closes.