To put the tennis scoring system as simply as possible, one must win:

• four points to win a game
• six games to win a set
• two (or, more rarely, three) sets to win a match
We'll call the players A and B.
By winning a coin toss or a spin of the racquet, A gets to choose one of the following:
• serve
• receive serve
• choose an end of the court
• have B choose

Let's say A chooses to serve. B then gets to choose an end of the court. A may serve from anywhere behind her baseline between the right singles sideline and the center mark. The serve must be struck before the ball bounces, and it must land in the service box diagonally opposite her. She gets two chances to get a serve in. If she misses both, she loses the point. If a serve that is otherwise good nicks the net on its way in, it is redone.
If A gets her serve in, B must return the ball, after exactly one bounce, into any part of A's singles court.

A and B must then return the ball, after no more than one bounce, into one another's singles court until one of them misses.
A will serve from the left side of her baseline for the second point of the game, and she will continue to alternate right and left for the start of each point of the game.

Let's say A wins the first point. At the start of the next point, she must announce the score, her point total first: "15 - love." (Love = 0.)
B wins the next point: "15 all."
B wins the next point: "15 - 30."
A wins the next point: "30 all."
A wins the next point: "40 - 30."

If A wins the next point, she wins the game.
If B wins the next point, the score is "40 all," which is called "deuce." At deuce, one player must win the next two points to win the game. If, at deuce, A wins the next point, she has the advantage, and the score is called "ad in," which means server's advantage. If B had won that point, the score would have been "ad out." If the player having the advantage wins the following point, he or she wins that game. If the player with the advantage loses the point, the score returns to deuce.

Playing a Set with a Tie-Break

At the end of the first and every odd-numbered game, the players switch ends of the court, and the player who served the previous game now receives serve. The server always begins a game by serving from the right. At the start of each game, she announces the number of games each has won, starting with her own score, for example, "3 - 2."

Once a player has won six games by a margin of two or more, he or she has won the set. If the score within a set reaches 6 - 6, the players may either continue to try to reach a margin of two (such as 8 - 6 or 9 - 7), or they may play a tie-break to decide the set. In tournament play, this choice will have been determined in advance, but recreational players often choose whichever option appeals to them at the moment.

In a standard "12-point tie break" (best of 12), one player must win seven points by a margin or two or more.

The player who received in the game preceding the tie-break serves the first point of the tie-break, starting from the right. The other player then serves the next two points, the first from the left, then the second from the right. Each player continues serving two points per turn. Points are scored with counting numbers ("1, 2, 3 . . ."). When the point total reaches six and each multiple of six, the players switch ends of the court.

If the previous set ended with an odd-numbered total of games, the players switch ends to begin the new set. (A tie-break counts as one game.) They will switch ends after every odd game through each set.

At the start of a new set, the player who received in the last game of the previous set (or received first in the tie-break) now serves.

 

In most tournaments, the first player to win two sets (best of three) wins the match. In a few events, such as men's Grand Slam tournaments, one must win three sets (best of five). Where time or fitness impose limits on the length of matches, a tie-break is sometimes used in place of a third set.

Recreational players often keep going until they're exhausted, even if one of them has won four sets in a row.

 

With traditional scoring, games can go back and forth from deuce to ad over and over. The "No Ad" variation on the scoring within games allows for a game to be won by a margin of one point. Instead of "15," "30," and "40" used to note points, players may use "1," "2," and "3." At "3 all," the receiver may choose whether to receive in the left or right service box