On 21 May 1881, the oldest nationwide tennis organization in the world[20] was formed, the United States National Lawn Tennis Association (now the United States Tennis Association) in order to standardize the rules and organize competitions.[21] The U.S. National Men's Singles Championship, now the US Open, was first held in 1881 at the Newport Casino, Newport, Rhode Island.[22] The U.S. National Women's Singles Championships were first held in 1887 in Philadelphia.[23]

To determine who serves first, you flip a coin or (more likely) spin a racket. Whoever wins the toss gets to decide one of four things: that she wants to serve first, that she wants to receive first, which side of the court she wants to start on (in which case, the opponent chooses who serves first), or that she wants to leave the choices up to her opponent.
Post-tensioned concrete is reinforced with a grid of high-strength sheathed steel tendons, or cables. While the concrete is curing, the cables are tensioned in both directions and held permanently under stress by anchoring them in a perimeter beam. This squeezing action keeps the concrete in compression, improving its tensile (or bending) strength. The more the concrete is squeezed together, the less likely it is that shrinkage cracks will develop or open. (See a more complete description of post-tensioning from the Post-Tensioning Institute.)
From 'No advantage'. Scoring method created by Jimmy Van Alen. The first player or doubles team to win four points wins the game, regardless of whether the player or team is ahead by two points. When the game score reaches three points each, the receiver chooses which side of the court (advantage court or deuce court) the service is to be delivered on the seventh and game-deciding point. Utilized by World Team Tennis professional competition, ATP tours, WTA tours, ITF Pro Doubles and ITF Junior Doubles.[57][58]
Tennis is a racket sport that can be played individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent's court. The object of the game is to maneuver the ball in such a way that the opponent is not able to play a valid return. The player who is unable to return the ball will not gain a point, while the opposite player will.