Lines

The lines that delineate the width of the court are called the baseline (furthest back) and the service line (middle of the court). The short mark in the center of each baseline is referred to as either the hash mark or the center mark. The outermost lines that make up the length are both called the doubles sideline. These are the boundaries used when doubles is being played. The area between the doubles sideline and the lines next to them is called the doubles alley, which is considered playable in doubles play. These lines next to the doubles sideline are the singles sidelines, and used as boundaries in singles play. The line that runs across the center of a player's side of the court is called the service line because the serve must be delivered into the area between the service line and the net on the receiving side. Despite its name, this is not where a player legally stands when making a serve. The line dividing the service line in two is called the center line or center service line. The boxes this center line creates are called the service boxes; depending on a player's position, he will have to hit the ball into one of these when serving. A ball is out only if none of it has hit the line upon its first bounce. All the lines are required to be 2 inches (51 mm) in width. The baseline can be up to 5 inches (130 mm) wide if so desired.

Types of courts

There are three main types of court surfaces. Depending on the materials used, each surface provides a difference in the speed and bounce of the ball, which in turn can affect the level of play of individual players. The three most common surfaces are:

Indoor courts are also used so play can continue year-round. Common indoor surfaces are hard, carpet, and clay.

Play of a single point

The players (or teams) start on opposite sides of the net. One player is designated the server, and the opposing player, or in doubles one of the opposing players, is the receiver. Service alternates between the two halves of the court. For each point, the server starts behind his baseline, between the center mark and the sideline. The receiver may start anywhere on their side of the net. When the receiver is ready, the server will serve, although the receiver must play to the pace of the server.

In a legal service, the ball travels over the net (without touching it) and into the diagonally opposite service box. If the ball hits the net but lands in the service box, this is a let service, which is void, and the server gets to retake that serve. The player can serve any number of let services in a point and they are always treated as voids and not as faults. Let services are somewhat unusual at recreational level and frequent at professional level. However, placing more than one let service in a single point takes a considerable amount of skill or luck. If the first service is otherwise faulty in any way, wide, long or not over the net, the serving player has a second attempt at service. There is also a "foot fault," which occurs when a player's foot touches the baseline or an extension of the center mark before the ball is hit. If the second service is also faulty, this is a double fault, and the receiver wins the point. However, if the serve is in, it is considered a legal service.

A legal service starts a rally, in which the players alternate hitting the ball across the net. A legal return consists of the player or team hitting the ball exactly once before it has bounced twice or hit any fixtures except the net, provided that it still falls in the server's court. The ball then travels back over the net and bounces in the court on the opposite side. The first player or team to fail to make a legal return loses the point.

A game point occurs in tennis whenever the player who is in the lead in the game needs only one more point to win the game. The terminology is extended to sets (set point), matches (match point), and even championships (championship point). For example, if the player who is serving has a score of 40-love, he has a triple game point (triple set point, etc.). Game points, set points, and match points are not part of official scoring and are not announced by the chair umpire in tournament play.

A break point occurs if the receiver, not the server, has a game point. It is of importance in professional tennis, since service breaks are rare enough to create a substantial advantage for the receiver in the men's game. The advantage to the server is much less in the women's game, but match analysts like to keep track of service breaks anyway. It may happen that the player who is in the lead in the game has more than one chance to score the winning point, even if his opponent should take the next point(s). For example, if the player who is serving has a score of 15-40, the receiver has a double break point. If the player in the lead wins any of the next two points, that player wins the game. Break points are not announced either.

A set consists of a sequence of games played with service alternating between games, ending when the count of games won meets certain criteria. Typically, a player wins a set when he wins at least six games and at least two games more than his opponent. When each player has won six games a tiebreaker is played. A tiebreaker, played under a separate set of rules, allows one player to win one more game and thus the set, to give a final set score of 7-6. Only in the final sets of matches at the Australian Open, the French Open, Wimbledon, Davis Cup, and Fed Cup are tie-breaks not played. A "love" set means that the loser of the set won zero games. For example if the score was 6 to 0, it would be 6 love.

Matches consist of an odd number of sets, the match winner being the player who wins more than half of the sets. The match ends as soon as this winning condition is met. Some matches may consist of five sets (the winner being the first to win three sets), while most matches are three sets (the winner being the first to win two sets). In tournament play, the chair umpire announces the end of the match with the well-known phrase "Game, set, match" followed by the winning team's name.

Officials

In most professional play and some amateur competition, there is an officiating head judge or chair umpire (usually referred to as the umpire), who sits in a raised chair to one side of the court. The umpire has absolute authority to make factual determinations. The umpire may be assisted by line judges, who determine whether the ball has landed within the required part of the court and who also call foot faults. There also may be a net judge who determines whether the ball has touched the net during service. In some tournaments, certain line judges, usually those who would be calling the serve, are replaced by electronic sensors that beep when an out call would have been made. In some open-tournament matches, players are allowed to challenge a limited number of close calls by means of instant replay. The U.S. Open, the Miami Masters, U.S. Open Series, and World Team Tennis started using a "challenge" system in 2006 and the Australian Open and Wimbledon introduced the system in 2007. This used the Hawk-Eye system and the rules were similar to those used in the NFL, where a player gets a limited number of instant-replay challenges per match/set. In clay-court matches, a call may be questioned by reference to the mark left by the ball's impact on the court surface.

The referee, who is usually located off the court, is the final authority about tennis rules. When called to the court by a player or team captain, the referee may overrule the umpire's decision if the tennis rules were violated (question of law) but may not change the umpire's decision on a question of fact. If, however, the referee is on the court during play, the referee may overrule the umpire's decision.

Ball boys or girls may be employed to retrieve balls, pass them to the players, and hand players their towels. They have no adjudicative role. In rare events (e.g., if they are hurt or if they have caused a hindrance), the umpire may ask them for a statement of what actually happened. The umpire may consider their statements when making a decision. In some leagues, especially junior leagues, players make their own calls, trusting each other to be honest. This is the case for many school and university level matches. However, the referee or referee's assistant can be called on court at a player's request, and the referee or assistant may change a player's call. In unofficiated matches, a ball is out only if the player entitled to make the call is sure that the ball is out.

A tennis match is intended to be continuous. Stamina is a relevant factor, so arbitrary delays are not permitted. In most cases, service is required to occur no more than 20 (ITF events) or 25 (ATP and WTA events) seconds after the end of the previous point. This is increased to 90 seconds when the players change ends (after every odd-numbered games), and a 120 second break is permitted between sets. Other than this, breaks are permitted only when forced by events beyond the players' control, such as rain, damaged footwear, damaged racquet, or the need to retrieve an errant ball. Should a player be determined to be stalling repeatedly, the chair umpire may initially give a warning followed by subsequent penalties of "point," "game," and default of the match for the player who is consistently taking longer than the allowed time limit.

A competent tennis player has eight basic shots in his or her repertoire: the serve, forehand, backhand, volley, half-volley, overhead smash, drop shot, and lob.

A serve (or, more formally, a "service") in tennis is a shot to start a point. The serve is initiated by tossing the ball into the air and hitting it (usually near the apex of its trajectory) into the diagonally opposite service box without touching the net. The serve may be hit under- or overhand.

Experienced players strive to master the conventional overhand serve to maximize its power and placement. The server may employ different types of serve including flat serve, topspin serve, slice serve and kick (American twist) serve. A reverse type of spin serve is hit in a manner that spins the ball opposite the natural spin of the server, the spin direction depending upon right- or left-handedness. If the ball is spinning counterclockwise, it will curve right from the hitter's point of view and curve left if spinning clockwise.

Some servers are content to use the serve simply to initiate the point; however, advanced players often try to hit a winning shot with their serve. A winning serve that is not touched by the opponent is called an "ace." If the receiver manages to touch it but fails to successfully return it, it is called a "service winner."

Players may use the continental, eastern, semi-western, or western grips during play. Different grips generally are used for different types of spin and shots.

For a right-handed player, the forehand is a stroke that begins on the right side of the body, continues across the body as contact is made with the ball, and ends on the left side of the body. There are various grips for executing the forehand and their popularity has fluctuated over the years. The most important ones are the continental, the eastern, the semi-western, and the western. No matter which grip is used, most forehands are generally executed with one hand holding the racquet, but there have been fine players with two-handed forehands.

For right-handed players, the backhand is a stroke that begins on the left side of their body, continues across their body as contact is made with the ball, and ends on the right side of their body. It can be executed with either one hand or with both and is generally considered more difficult to master than the forehand. Two hands give the player more power, while one hand can generate a slice shot, applying backspin on the ball to produce a low trajectory bounce.

Other shots

A volley is made in the air before the ball bounces, generally near the net, and is usually made with a stiff-wristed punching motion to hit the ball into an open area of the opponent's court. The half volley is made by hitting the ball on the rise just after it has bounced, once again generally in the vicinity of the net. The swinging volley is hit out of the air as the player approaches the net. It is an offensive shot used to take preparation time away from the opponent. From a poor defensive position on the baseline, the lob can be used as either an offensive or defensive weapon, hitting the ball high and deep into the opponent's court to either enable the lobber to get into better defensive position or to win the point outright by hitting it over the opponent's head. If the lob is not hit deeply enough into the other court, however, the opponent may then hit an overhead smash, a hard, serve-like shot, to try to end the point. Finally, if an opponent is deep in his court, a player may suddenly employ an unexpected drop shot, softly tapping the ball just over the net so that the opponent is unable to run in fast enough to retrieve it. No matter what shot it is, a forehand, backhand, serve or volley, putting spin on the ball, knowing how to use spin to its best advantage, is what separates the top players from the rest.

Tournaments

Tournaments are often organized by gender and number of players. Common tournament configurations include men's singles, women's singles, and doubles, where two players play on each side of net. Tournaments may be arranged for specific age groups, with upper age limits for youth and lower age limits for senior players.

Grand Slam tournaments

The four Grand Slam tournaments are considered to be the most prestigious tennis tournaments in the world. They are held annually and include, in chronological order, the Australian Open, the French Open, Wimbledon, and the US Open. Apart from Davis Cup, Fed Cup, and Hopman Cup, they are the only tournaments regulated by the International Tennis Federation (ITF).

Aside from the historical significance of these events, they also carry larger prize funds than any other tour event and are worth double the number of ranking points to the champion than in the next echelon of tournaments, the Tennis Masters Series (men) and Tier I events (women).[28] [29] Another distinguishing feature is the number of players in the singles draw, 128, more than any other professional tennis tournament. This draw is composed of 32 seeded players, other players ranked in the world's top 100, qualifiers, and players who receive invitations through wild cards. Grand Slam men's tournaments have best-of-five set matches throughout. Grand Slam tournaments are among the small number of events that last two weeks, the others being the Pacific Life Open in Indan Wells, California and the Sony Ericsson Open in Key Biscayne, Florida. Currently, the Grand Slam tournaments are the only tour events that have mixed doubles contests.

Tennis Masters Series

The Tennis Masters Series is a group of nine tournaments that form the second-highest echelon in men's tennis. Each event is held annually, and a win at one of these events is worth 500 ranking points. When the Association of Tennis Professionals, led by Hamilton Jordan, began running the men's tour in 1990, the directors designated the top nine tournaments, outside of the Grand Slam events, as "Super Nine" events. These eventually became the Tennis Masters Series. In November at the end of the tennis year, the world's top eight players compete in the Tennis Masters Cup, a tournament with a rotating locale. It is currently held in Shanghai, < >China, and will move to London in 2009.

In 2009, the Tennis Masters Series will undergo several changes. The series will be renamed again, this time as the "1,000 Series," a reference to the number of points the champion of each event will garner. (All other tournaments will have their ranking points adjusted proportionately.)  The Tennis Masters Cup, in addition to its relocation, will be renamed the ATP World Tour Final. However, Shanghai will host a new 1,000 Series event. The Monte Carlo and Hamburg events were originally downgraded; however, the Monte Carlo tournament was eventually granted 1,000 Series status, with the exception being that the event would not be mandatory. The ATP also plans to be more stringent in its examination of players who withdraw from 1,000 Series events. Each player who withdraws will be examined by a medical panel. The ATP plans to fine, and even suspend, players who disregard these rules.

International Series

The International Series for men is split in to two categories, both run by the ATP: the International Series and International Series Gold. Like the Tennis Masters Series, these events offer various amounts of prize money, and some regular International Series events offer larger prize monies than International Series Gold tournaments. The Barclays Dubai Tennis Championships offer the largest financial incentive to players, with total prize money of US$1,426,000.

Challenger Series and Futures Tournaments

The Challenger Series for men is the lowest level of tournament administered by the ATP. It is composed of roughly 160 events and, as a result, features a more diverse range of countries hosting events. The majority of players use the Challenger Series to work their way up the rankings. The Challenger Series offers prize funds of between US$25,000 to US$150,000.

Below the Challenger Series are the Futures Tournaments, the main events on the < >ITF Men's Circuit. These tournaments also contribute towards a player's ATP rankings points. Futures Tournaments offer prize funds of between US$10,000 and US$15,000; however, futures status is granted only to events offering a total of US$30,000, meaning that two or three tournaments are played. Approximately 400 Futures Tournaments are played each year.

Male players who have played at least part of their careers during the open era and who have won at least two Grand Slam singles titles are as follows: Pete Sampras (14), Roger Federer (12), Roy Emerson (12), Rod Laver (11), Bj?Borg (11), Ken Rosewall (8), Jimmy Connors (8), Ivan Lendl (8), Andre Agassi (8), John Newcombe (7), John McEnroe (7), Mats Wilander (7), Boris Becker (6), Stefan Edberg (6), Jim Courier (4), Guillermo Vilas (4), Arthur Ashe (3), Jan Kodes (3), Gustavo Kuerten (3), Rafael Nadal (3), Stan Smith (2), Ilie N㳴ase (2), Johan Kriek (2), Lleyton Hewitt (2), Yevgeny Kafelnikov (2), Patrick Rafter (2), Sergi Bruguera (2), and Marat Safin (2).

Female players who have played at least part of their careers during the open era and who have won at least two Grand Slam singles titles are as follows: Margaret Court (24), Steffi Graf (22), Chris Evert (18), Martina NavrᴩlovἯa> (18), Billie Jean King (12), Monica Seles (9), Serena Williams (8), Justine Henin (7), Evonne Goolagong Cawley (7), Venus Williams (6), Martina Hingis (5), Hana Mandl�vἯa> (4), Arantxa Sᮣhez Vicario (4), Maria Sharapova (3), Virginia Wade (3), Lindsay Davenport (3), Jennifer Capriati (3), Nancy Richey Gunter (2), Tracy Austin (2), Mary Pierce (2), and Am鬩e Mauresmo (2).