basketball history

Game played between two teams of five players each on a rectangular court, usually indoors. Each team tries to score by tossing the ball through the opponent's goal, an elevated horizontal hoop and net called a basket.

The only major sport strictly of U.S. origin, basketball was invented by James Naismith (1861–1939) on or about December 1, 1891, at the International Young Men's Christian Association (YMCA) Training School (now Springfield College), Springfield, Massachusetts, where Naismith was an instructor in physical education.

For that first game of basketball in 1891, Naismith used as goals two half-bushel peach baskets, which gave the sport its name. The students were enthusiastic. After much running and shooting, William R. Chase made a midcourt shot—the only score in that historic contest. Word spread about the newly invented game, and numerous associations wrote Naismith for a copy of the rules, which were published in the January 15, 1892, issue of the Triangle, the YMCA Training School's campus paper.

While basketball is competitively a winter sport, it is played on a 12-month basis—on summer playgrounds, in municipal, industrial, and church halls, in schoolyards and family driveways, and in summer camps—often on an informal basis between two or more contestants. Many grammar schools, youth groups, municipal recreation centres, churches, and other organizations conduct basketball programs for youngsters of less than high school age. Jay Archer, of Scranton, Pennsylvania, introduced “biddy” basketball in 1950 for boys and girls under 12 years of age, the court and equipment being adjusted for size.

In the early years the number of players on a team varied according to the number in the class and the size of the playing area. In 1894 teams began to play with five on a side when the playing area was less than 1,800 square feet (167.2 square metres); the number rose to seven when the gymnasium measured from 1,800 to 3,600 square feet (334.5 square metres) and up to nine when the playing area exceeded that. In 1895 the number was occasionally set at five by mutual consent; the rules stipulated five players two years later, and this number has remained ever since.

Since Naismith and five of his original players were Canadians, it is not surprising that Canada was the first country outside the United States to play the game. Basketball was introduced in France in 1893, in England in 1894, in Australia, China, and India soon thereafter, and in Japan in 1900.

While basketball helped swell the membership of YMCAs because of the availability of their gyms, within five years the game was outlawed by various associations because gyms that had been occupied by classes of 50 or 60 members were now monopolized by only 10 to 18 players. The banishment of the game induced many members to terminate their YMCA membership and to hire halls to play the game, thus paving the way to the professionalization of the sport.

Originally, players wore one of three styles of uniforms: knee-length football trousers; jersey tights, as commonly worn by wrestlers; or short padded pants, forerunners of today's uniforms, plus knee guards. The courts often were of irregular shape with occasional obstructions such as pillars, stairways, or offices that interfered with play. In 1903 it was ruled that all boundary lines must be straight. In 1893 the Narragansett Machinery Co. of Providence, Rhode Island, marketed a hoop of iron with a hammock style of basket. Originally a ladder, then a pole, and finally a chain fastened to the bottom of the net was used to retrieve a ball after a goal had been scored. Nets open at the bottom were adopted in 1912–13. In 1895–96 the points for making a basket (goal, or field goal) were reduced from three to two, and the points for making a free throw (shot uncontested from a line in front of the basket after a foul had been committed) were reduced from three to one.

Baskets were frequently attached to balconies, making it easy for spectators behind a basket to lean over the railings and deflect the ball to favour one side and hinder the other; in 1895 teams were urged to provide a 4-by-6-foot (1.2-by-1.8-metre) screen for the purpose of eliminating interference. Soon after, wooden backboards proved more suitable. Glass backboards were legalized by the professionals in 1908–09 and by colleges in 1909–10. In 1920–21 the backboards were moved 2 feet (0.6 metre), and in 1939–40 4 feet, in from the end lines to reduce frequent stepping out-of-bounds. Fan-shaped backboards were made legal in 1940–41.

A soccer ball (football) was used for the first two years. In 1894 the first basketball was marketed. It was laced, measured close to 32 inches (81 cm), or about 4 inches (10 cm) larger than the soccer ball, in circumference, and weighed less than 20 ounces (567 grams). By 1948–49, when the laceless molded ball was made official, the size had been set at 30 inches (76 cm).

The first college to play the game was either Geneva College (Beaver Falls, Pennsylvania) or the University of Iowa. C.O. Bemis heard about the new sport at Springfield and tried it out with his students at Geneva in 1892. At Iowa, H.F. Kallenberg, who had attended Springfield in 1890, wrote Naismith for a copy of the rules and also presented the game to his students. At Springfield, Kallenberg met Amos Alonzo Stagg, who became athletic director at the new University of Chicago in 1892. The first college basketball game with five on a side was played between the University of Chicago and the University of Iowa in Iowa City on January 18, 1896. The University of Chicago won, 15–12, with neither team using a substitute. Kallenberg refereed that game—a common practice in that era—and some of the spectators took exception to some of his decisions.

The colleges formed their own rules committee in 1905, and by 1913 there were at least five sets of rules: collegiate, YMCA–Amateur Athletic Union, those used by state militia groups, and two varieties of professional rules. Teams often agreed to play under a different set for each half of a game. To establish some measure of uniformity, the colleges, Amateur Athletic Union, and YMCA formed the Joint Rules Committee in 1915. This group was renamed the National Basketball Committee (NBC) of the United States and Canada in 1936 and until 1979 served as the game's sole amateur rule-making body. In that year, however, the colleges broke away to form their own rules committee, and during the same year the National Federation of State High School Associations likewise assumed the task of establishing separate playing rules for the high schools. The National Collegiate Athletic Association (NCAA) Rules Committee for men is a 12-member board representing all three NCAA divisions. It has six members from Division I schools and three each from Divisions II and III. It has jurisdiction over colleges, junior colleges, the National Association of Intercollegiate Athletics (NAIA), and Armed Forces basketball. There is a similar body for women's play.

Basketball grew steadily but slowly in popularity and importance in the United States and internationally in the first three decades after World War II. Interest in the game deepened as a result of television exposure, but with the advent of cable television, especially during the 1980s, the game's popularity exploded at all levels. Given a timely mix of spectacular players—such as Earvin (“Magic”) Johnson, Julius Erving (“Dr. J”), Larry Bird, and Michael Jordan—and the greatly increased exposure, basketball moved quickly to the forefront of the American sporting scene, alongside such traditional leaders as baseball and football. Four areas of the game developed during this period: U.S. high school and college basketball, professional basketball, women's basketball, and international basketball.

Basketball at the high school and college levels developed from a structured, rigid game in the early days to one that is often fast-paced and high-scoring. Individual skills improved markedly, and, although basketball continued to be regarded as the ultimate team game, individualistic, one-on-one performers came to be not only accepted but used as an effective means of winning games.

In the early years games were frequently won with point totals of less than 30, and the game, from the spectator's viewpoint, was slow. Once a team acquired a modest lead, the popular tactic was to stall the game by passing the ball without trying to score, in an attempt to run out the clock. The NBC, seeing the need to discourage such slowdown tactics, instituted a number of rule changes. In 1932–33 a line was drawn at midcourt, and the offensive team was required to advance the ball past it within 10 seconds or lose possession. Five years later, in 1937–38, the centre jump following each field goal or free throw was eliminated. Instead, the defending team was permitted to inbound the ball from the out-of-bounds line underneath the basket. Decades passed before another alteration of like magnitude was made in the college game. After experimentation the NCAA Rules Committee installed a 45-second shot clock in 1985, restricting the time a team could control the ball before shooting, and one year later it implemented a three-point shot rule for baskets made beyond a distance of 19.75 feet (6.0 metres).

More noticeable alteration in the game came at both the playing and coaching levels. Stanford University's Hank Luisetti was the first to use and popularize the one-hand shot in the late 1930s. Until then the only outside attempts were two-handed push shots. In the 1950s and '60s a shooting style evolved from Luisetti's push-off one hander to a jump shot, which is released at the top of the jump. West Virginia University guard Jerry West and Purdue University's Rick Mount were two players who demonstrated the devastating effectiveness of this shot.

Coaching strategy changed appreciably over the years. Frank W. Keaney, coach at Rhode Island University from 1921 to 1948, is credited with introducing the concept of “fast break” basketball, in which the offensive team rushes the ball upcourt hoping to get a good shot before the defense can get set. Another man who contributed to a quicker pace of play, particularly through the use of the pressure defense, was Adolph Rupp, who became the University of Kentucky's coach in 1931 and turned its program into one of the most storied in basketball history.

Defensive coaching philosophy, similarly, has undergone change. Whereas pioneer coaches such as Henry Iba of Oklahoma A&M University (now Oklahoma State University) or Long Island University's Clair Bee taught strictly a man-to-man defense, the zone defense, developed by Cam Henderson of Marshall University in West Virginia, later became an integral part of the game (see below Play of the game).

Over the years one of the rules makers' chief concerns was to neutralize the advantage of taller players. At 6 feet 5 inches (1.96 metres) Joe Lapchick was considered very tall when he played for the Original Celtics in the 1920s, but, as even taller players appeared, rules were changed in response. To prevent tall players from stationing themselves near the basket, a rule was instituted in 1932–33 prohibiting the player with the ball from standing inside the foul lane with his back to the basket for more than three seconds; the three-second rule later applied to any attacking player in the foul lane. In 1937–38 a new rule forbade any player from touching the ball when it was in the basket or on its rim (basket interference), and in 1944–45 it became illegal for any defending player to touch the ball on its downward flight toward the basket (goaltending).

Nevertheless, with each passing decade, the teams with the tallest players tended to dominate. Bob Kurland (7 feet [2.13 metres]) led Oklahoma A&M to two NCAA championships in the 1940s and led the nation in scoring in 1945–46. In the same era George Mikan (6 feet 10 inches [2.08 metres]) scored more than 550 points in each of his final two seasons at DePaul University before going on to play nine professional seasons in which he scored more than 11,000 points. Mikan was an outstanding player, not only because of his size but because of his ability to shoot sweeping hook shots with both hands.

In the 1950s Bill Russell (6 feet 9 inches [2.06 metres]) led the University of San Francisco to two NCAA championships before going on to become one of the greatest centres in professional basketball history. Wilt Chamberlain (7 feet 1 inch [2.16 metres]) played at the University of Kansas before turning professional in the late 1950s and is regarded as the greatest all-around big man ever to play. It remained, however, for Lew Alcindor (later Kareem Abdul-Jabbar), also 7 feet 1 inch, to most influence the rules. After his sophomore year (1966–67) at the University of California at Los Angeles (UCLA), the dunk shot was banned from collegiate basketball, ostensibly because the rules committee felt, again, that the big men had too great an advantage. The rule was rescinded beginning with the 1976–77 season, and the dunk shot became an important part of the game, electrifying both fans and players.

So, too, have the small- and medium-size players affected the game's development. Bob Cousy, playing at Holy Cross College and later for the Boston Celtics, was regarded as one of the game's first great playmakers. He was among the first to use the behind-the-back pass and between-the-legs dribble as effective offensive maneuvers. Later such smaller players as Providence College's Ernie DiGregorio, the University of North Carolina's Phil Ford, and Indiana's Isiah Thomas proved the importance of their role. Between those two extremes are players such as Louisiana State University's Pete Maravich, who set an all-time collegiate scoring record of 44.5 points per game in the 1969–70 season; Magic Johnson, the point guard who led Michigan State University to a championship in 1979 and the Los Angeles Lakers to several NBA championships; Oscar Robertson, a dominating performer for the University of Cincinnati in the late 1950s and for the Milwaukee Bucks in the 1970s; Larry Bird of Indiana State University, a forward of exceptional versatility who led the Boston Celtics to several championships; and Michael Jordan, a great all-around player with the University of North Carolina in the 1980s who is widely considered the best professional player in the history of the sport.

Nothing influenced the college game's growth more than television, however. The NCAA championship games were televised nationally from 1963, and by the 1980s all three major television networks were telecasting intersectional college games during the November-to-March season. Rights fees for these games soared from a few million dollars to well over $50 million by the late 1980s. As for broadcasting the NCAA finals, a television contract that began in 2003 gave the NCAA an average of $545 million per year for the television rights; this exponential growth in broadcast fees reflected the importance of these games to both networks and advertisers.

Profits such as these inevitably attract gamblers, and in the evolution of college basketball the darkest hours have been related to gambling scandals. But, as the game began to draw more attention and generate more income, the pressure to win intensified, resulting in an outbreak of rules violations, especially with regard to recruitment of star players.

The most identifiable phase of college basketball in America is the postseason tournament held in March—popularly known as March Madness. Interest in the NCAA tournament paralleled the growth of the game. The first basketball tournament was staged by the Amateur Athletic Union in 1897 and was won by New York City's 23rd Street YMCA, later to become a traveling professional team known as the New York Wanderers. Although the YMCA was prominently identified with the game in its early years, it did not hold its first national tournament until 1923, and that event took place until 1962. The first national tournament for colleges was held in 1937 and was conducted by an organization in Kansas City, Missouri, that later became the NAIA.

New York City basketball writers organized the first National Invitation Tournament (NIT) in 1938, but a year later the New York City colleges took control of the event. Until the early 1950s the NIT was considered the most prestigious American tournament, but, with the growth of the college-run NCAA championship, the NIT became a consolation event for teams that failed to make the NCAA selections.

The first NCAA tournament was played in 1939, and its growth took place in three stages. The first era ran through 1964, when it was essentially a tournament for champions of various conferences. There were just eight teams in the 1939 field, and by 1963 it had been expanded to 25 teams, all champions of their respective conferences, plus several successful independent teams. The most outstanding teams of the 1940s and '50s participated in both the NCAA and NIT tournaments, but, after the gambling scandals that followed the 1950 NIT championship, a rule was passed prohibiting a team from playing in both. Afterward the NCAA tournament progressively outgrew the NIT.

In 1964 the second era dawned as the UCLA Bruins, coached by John Wooden, began a period of domination over the NCAA field. From that season until 1975 Wooden led his teams to 10 NCAA championships. Only championships won by Texas Western University (now University of Texas at El Paso) in 1966 and North Carolina State in 1974 interrupted UCLA's reign. In the eyes of many, the UCLA dynastic period probably had a regressive effect on the game's growth; a sport with such high predictability lost some of its attractiveness.

The third growth stage came with the end of UCLA's dominance. Champions began to emerge from all sections of the country. From the field of 25 in 1974, the NCAA tournament expanded to 64 participants, including not only conference championship teams but other outstanding teams from the same conferences as well. Three weeks of play culminate with the Final Four weekend, an event now comparable in general public interest and media attention to the Super Bowl and World Series. Championships at the Division II, Division III, and NAIA levels also continued to grow in interest, reaping some of the fallout from the popularity of Division I.

About 17,000 high schools in the United States have basketball teams. All 50 states annually conduct statewide tournaments. Most states also conduct annual tournaments for girls.

The professional game first prospered largely in the Middle Atlantic and New England states. Trenton (New Jersey) and the New York Wanderers were the first great professional clubs, followed by the Buffalo (New York) Germans, who started out in 1895 as 14-year-old members of the Buffalo YMCA and, with occasional new members, continued for 44 years, winning 792 out of 878 games.

A group of basketball stylists who never received the acclaim they deserved (because in their heyday they played for various towns) consisted of Edward and Lew Wachter, Jimmy Williamson, Jack Inglis, and Bill Hardman. They introduced the bounce pass and long pass as offensive weapons and championed the rule (adopted 1923–24) that made each player, when fouled, shoot his own free throw.

Before World War II the most widely heralded professional team was the Original Celtics, which started out in 1915 as a group of youngsters from New York City, kept adding better players in the early 1920s, and became so invincible that the team disbanded in 1928, only to regroup in the early 1930s as the New York Celtics. They finally retired in 1936. The Celtics played every night of the week, twice on Sundays, and largely on the road. During the 1922–23 season they won 204 of 215 games.

Another formidable aggregation was the New York Renaissance (the Rens), organized by Robert Douglas in 1923 and regarded as the strongest all-black team of all time. During the 1925–26 campaign they split a six-game series with the Original Celtics. During the 1932–33 season the Rens won 88 consecutive games. In 1939 they defeated the Harlem Globetrotters and the Oshkosh All Stars in the world championship pro tournament in Chicago. Among the great professional clubs were the teams of Fond du Lac, Wisconsin, and East Liverpool, Ohio, as well as the New York Nationals, the Paterson (New Jersey) Crescents, and the South Philadelphia Hebrew All Stars—better known as the Sphas.

The first professional league was the National Basketball League (NBL), formed in 1898. Its game differed from the college game in that a chicken-wire cage typically surrounded the court, separating players from often hostile fans. (Basketball players were long referred to as cagers.) The chicken wire was soon replaced with a rope netting, off which the players bounced like prizefighters in a boxing ring. The cage also kept the ball from going out-of-bounds, thus quickening the pace of play. In these early days players were also permitted to resume dribbling after halting. Despite the lively action of the game, the NBL and other early leagues were short-lived, mostly because of the frequent movement of players, who sold their services on a per-game basis. With players performing for several cities or clubs within the same season, the leagues suffered games of unreliable quality and many financially unstable franchises.

The Great Depression of the 1930s hurt professional basketball, and a new NBL was organized in 1937 in and around the upper Midwest. Professional basketball assumed major league status with the organization of the new Basketball Association of America (BAA) in 1946 under the guidance of Walter A. Brown, president of the Boston Garden. Brown contended that professional basketball would succeed only if there were sufficient financial support to nurse the league over the early lean years, if the game emphasized skill instead of brawling, and if all players were restricted to contracts with a reserve rule protecting each team from raiding by another club. Following a costly two-year feud, the BAA and the NBL merged in 1949 to form the National Basketball Association (NBA).

To help equalize the strength of the teams, the NBA established an annual college draft permitting each club to select a college senior in inverse order to the final standings in the previous year's competition, thus enabling the lower-standing clubs to select the more talented collegians. In addition, the game was altered through three radical rule changes in the 1954–55 season:

After a struggle to survive, including some large financial losses and several short-lived franchises, the NBA took its place as the major professional basketball league in the United States. A rival 11-team American Basketball Association (ABA), with George Mikan as commissioner, was launched in the 1967–68 season, and a bitter feud developed with the NBA for the top collegiate talent each season. In 1976 the ABA disbanded, and four of its teams were taken into the NBA.

The NBA grew increasingly popular through the 1980s. Attendance records were broken in that decade by most of the franchises, a growth pattern stimulated at least in part by the increased coverage by cable television. The NBA has a total of 30 teams organized into Eastern and Western conferences and further divided into six divisions. In the Eastern Conference the Atlantic Division comprises the Boston Celtics, the New Jersey Nets (in East Rutherford), the New York Knicks (in New York City), the Philadelphia 76ers, and the Toronto Raptors; the Central Division is made up of the Chicago Bulls, the Cleveland (Ohio) Cavaliers, the Detroit (Michigan) Pistons, the Indiana Pacers (in Indianapolis), and the Milwaukee (Wisconsin) Bucks; the Southeast Division comprises the Atlanta (Georgia) Hawks, the Charlotte (North Carolina) Bobcats, the Miami (Florida) Heat, the Orlando (Florida) Magic, and the Washington (D.C.) Wizards. In the Western Conference the Southwest Division comprises the Texas-based Dallas Mavericks, Houston Rockets, and San Antonio Spurs, the Memphis (Tennessee) Grizzlies, and the New Orleans (Louisiana) Hornets; the Northwest Division is made up of the Denver (Colorado) Nuggets, the Minnesota Timberwolves (in Minneapolis), the Portland (Oregon) Trail Blazers, the Seattle (Washington) SuperSonics, and the Utah Jazz (in Salt Lake City); the Pacific Division comprises the Phoenix (Arizona) Suns and the California-based Golden State Warriors (in Oakland), Los Angeles Clippers, Los Angeles Lakers, and Sacramento Kings. The play-offs follow the traditional 82-game schedule, involving 16 teams and beginning in late April. Played as a best-of-seven series, the final pairings stretch into late June.

Although basketball is traditionally a winter game, the NBA still fills its arenas and attracts a national television audience in late spring and early summer. As the popularity of the league grew, player salaries rose to an annual average of $3.7 million in 2003. Some superstars earned nearly $30 million yearly for the 2003–04 season. The NBA has a salary cap that limits (at least theoretically, as loopholes allow many teams to exceed the cap) the total amount a team can spend on salaries in any given season. For 2003–04 the team salary cap was $43.84 million.

In 2001 the NBA launched the National Basketball Development League (NBDL). The league served as a kind of “farm system” for the NBA. Through its first 50 years the NBA did not have an official system of player development or a true minor league system for bringing up young and inexperienced players such as exists in major league baseball. College basketball has been the area from which the NBA did the vast majority of its recruiting. By 2000 this had begun to change somewhat, as players began to be drafted straight out of high school. At the turn of the 21st century the NBA was reviewing whether to continue this policy or to set a minimum age limit for players entering the league.

Clara Baer, who introduced basketball at the H. Sophie Newcomb College for Women in New Orleans, influenced the women's style of play with her set of women's rules, published in 1895. On receiving a diagram of the court from Naismith, Baer mistook dotted lines, indicating the areas in which players might best execute team play, to be restraining lines, with the result that the forwards, centres, and guards were confined to specified areas. This seemed appropriate because many felt that the men's game was too strenuous for women.

Women's rules over the years frequently have been modified. Until 1971 there were six players on a team, and the court was so divided that the three forwards played in the frontcourt and did all the scoring while the three guards covered the backcourt. Senda Berenson staged the first women's college basketball game in 1893 when her freshman and sophomore Smith College women played against one another. In April 1895 the women of the University of California (Berkeley) played Stanford University. Despite a multitude of hindrances (such as being thought unladylike), women's basketball gradually secured a foothold. In 1971, when women's rules were changed to reduce the number on a team from six players to five and women were freed from the limits imposed by the half-court game, the level of individual skills and competition quickly rose.

In the early 1980s control of the women's college game was shifted from the Association for Intercollegiate Athletics for Women (AIAW) to the NCAA, a move that not only streamlined the operation and made it more efficient but also added to the visibility of women's basketball. The women's NCAA championship tournament runs concurrently with the men's, and many of the games are nationally televised. Women's basketball became an Olympic sport in 1976.

Individual women stars have been heavily recruited by colleges, but the players frequently found that there was no opportunity for them to play beyond the college level. Leagues were occasionally formed, such as the Women's Professional Basketball League (WPBL). Begun in 1978, the league lasted only three years. Eventually filling the void was the Women's National Basketball Association (WNBA). Aligned with the powerful NBA, the WNBA held its inaugural season in 1997 with eight teams. By 2004 the league had grown to 13 teams. The Eastern Conference consisted of the Charlotte Sting, Connecticut Sun (in Uncasville), Detroit Shock, Indiana Fever (in Indianapolis), New York Liberty (in New York City), and Washington (D.C.) Mystics. The Western Conference comprised the Houston Comets, Los Angeles Sparks, Minnesota Lynx (in Minneapolis), Phoenix Mercury, Sacramento Monarchs, San Antonio Silver Stars, and Seattle Storm. Women's professional basketball is played during the summer months when the television schedule for sporting events is less crowded.

The success of international basketball was greatly advanced by Forrest C. (“Phog”) Allen, a Naismith disciple and a former coach at the University of Kansas, who led the movement for the inclusion of basketball in the Olympic Games in 1936 and thereafter. Basketball has also been played in the Pan-American Games since their inauguration in 1951. The international game is governed by the Fédération Internationale de Basketball Amateur (FIBA). World championships began in 1950 for men and in 1953 for women. Under international rules the court differs in that there is no frontcourt or backcourt, and the free throw lanes form a modified wedge shape. There are some differences in rules, including those governing substitutions, technical and personal fouls, free throws, intermissions, and time-outs. Outside the United States there are few places that strictly separate amateur from professional athletes.

Basketball has caught on particularly well in Italy. The Italian professional basketball league (Lega Basket) is highly regarded and popular in that country. Spain also has several basketball leagues, the main one being the ACB (Asociación de Clubes de Baloncesto). The other major centre of European basketball is eastern Europe, particularly the Balkans. Although the European leagues are not formally aligned with the American NBA, there are links between European and American basketball. It is not uncommon for European players to be drafted by the NBA, nor is it uncommon for American players to play in Europe. American players in the European leagues tend to be older players who have finished successful NBA careers in the United States or younger players who have not yet been drafted into the NBA.

The standard American basketball court is in the shape of a rectangle 50 feet (15.2 metres) by 94 feet (28.7 metres); high school courts may be slightly smaller. There are various markings on the court, including a centre circle, free throw lanes, and a three-point line, that help regulate play. A goal, or basket, 18 inches (46 cm) in diameter is suspended from a backboard at each end of the court. The metal rim of the basket is 10 feet (3.0 metres) above the floor. In the professional game the backboard is a rectangle, 6 feet (1.8 metres) wide and 3.5 feet (1.1 metres) high, made of a transparent material, usually glass; it may be 4 feet (1.2 metres) high in college. The international court varies somewhat in size and markings. The spherical inflated ball measures 29.5 to 30 inches (74.9 to 76 cm) in circumference and weighs 20 to 22 ounces (567 to 624 grams). Its covering is leather or composition.

The rules governing play of the game are based on Naismith's five principles requiring a large, light ball, handled with the hands; no running with the ball; no player being restricted from getting the ball when it is in play; no personal contact; and a horizontal, elevated goal. The rules are spelled out in specific detail by the governing bodies of the several branches of the sport and cover the playing court and equipment, officials, players, scoring and timing, fouls, violations, and other matters. The officials include a referee and two umpires in college play (two referees and a crew chief in NBA play), two timers, and two scorekeepers. One player on each team acts as captain and speaks for the team on all matters involving the officials, such as interpretation of rules. Professional and high school games are divided into four periods, college games into two.

Since the 1895–96 season, a field goal has scored two points and a free throw one point. When the ABA was founded in 1967, it allowed three points for shots made from outside a boundary line set 25 feet (7.6 metres) from the basket. With varying distances, the change was adopted officially by the NBA in 1979 and, in 1985, by colleges.

Basketball is a rough sport, although it is officially a noncontact game. A player may pass or bounce (dribble) the ball to a position whereby he or a teammate may try for a basket. A foul is committed whenever a player makes such contact with an opponent as to put him at a disadvantage; for the 2001–02 season the NBA approved a rule change that eliminated touch fouls, meaning brief contact initiated by a defensive player is allowable if it does not impede the progress of the offensive player. If a player is fouled while shooting and the shot is good, the basket counts and he is awarded one free throw (an unhindered throw for a goal from behind the free throw, or foul, line, which is 15 feet [4.6 metres] from the backboard); if the shot misses, he gets a second free throw. If a foul is committed against a player who is not shooting, then his team is awarded either the possession of the ball or a free throw if the other team is in a penalty situation. A team is in a penalty situation when it has been called for a set number of fouls in one period (four in professional and international play and six in the college game). Infractions such as unsportsmanlike conduct or grasping the rim are technical fouls, which award to the opposition a free throw and possession of the ball. Overly violent fouls are called flagrant fouls and also result in free throws and possession for the opposition. Players are allowed a set number of personal fouls per game (six in the NBA, five in most other competitions) and are removed from the game when the foul limit is reached.

Other common infractions occur when a player (with the ball) takes an excessive number of steps or slides; fails to advance the ball within five seconds while being “closely guarded”; causes the ball to go out-of-bounds; steps over the foul line while shooting a free throw; steps over the end line or sideline while tossing the ball in to a teammate, or fails to pass the ball in within five seconds; runs with, kicks, or strikes the ball with his fist; dribbles a second time after having once concluded his dribble (double dribble); remains more than three seconds in his free throw lane while he or his team has the ball; causes the ball to go into the backcourt; retains the ball in the backcourt more than 10 seconds, changed in the NBA to 8 seconds for 2001–02; or fails to shoot within the time allotted by the shot clock (24 seconds in the NBA and international play, 30 in the WNBA, and 35 in college). The penalty is loss of the ball—opponents throw the ball in from the side.