Red Haired Girl On The Tennis Court

The rules of tennis have not changed much since the 1890s. Two exceptions are that from 1908 to 1960 the server had to keep one foot on the ground at all times, and then the adoption of the tie-break in the 1970s. A recent addition to professional tennis has been the adoption of electronic review technology coupled with a point challenge system, which allows a player to challenge the line (or chair) umpire's call of a point. Players have unlimited opportunity to challenge, but once three incorrect challenges are made in a set, they cannot challenge again until the next set. If the set goes to a tie break, players are given one additional opportunity to challenge the call. This electronic review, currently called Hawk-Eye, is available at a limited number of high-level ATP and WTA tournaments.
Tennis is enjoyed by millions of recreational players and is also a hugely popular worldwide spectator sport, especially the four Grand Slam tournaments (also referred to as the "Majors"): the Australian Open played on hard courts, the French Open played on red clay courts, Wimbledon played on grass courts, and the US Open played also on hard courts.