At the professional level, games are played in four quarters of
10 (international) or 12 minutes (NBA) each. Games take longer
than this allotted game time, since the game clock only runs
when the ball is in play. This is called using a stop clock,
as the clock stops when the ball is not in play, for example,
when it goes out of bounds or a foul is committed. Fifteen minutes
are allowed at half-time, and two minutes are allowed at other
intervals. At lower levels, various time regulations exist.
Time-outs and substitutions are permitted during a game. A substitution
is that of one player on the court for another on the team bench.
A time-out is a clock stoppage requested by the coach of either
team, in which he can discuss tactics etc. A time-out lasts one
minute in international basketball and either 100 seconds, 60 seconds
or 20 seconds in NBA basketball. A limited number of time-outs
is allowed. (In international basketball, 2 time-outs are allowed
in the first two periods, 3 in the last two periods, and 1 in each
extra period. In NBA basketball, six 100/60-second time-outs are
allowed in the entire game of which a maximum of three can be in
the last quarter, and 3 100/60-second time-outs in each extra period,
as well as one 20-second time-out per half.)
The only essential equipment in basketball is a court, two baskets
with backboards and a basketball. At competition level, clocks
are necessary to regulate game time. Professional and international
games often call for more equipment, to assist in administration
and officiating. This can include shot clocks, scorer's tables,
and whistle-operated stop-clock systems.
The men's ball's circumference ranges between 749 and 762 mm (29.48
and 30 in); its diameter 238 to 242 mm (9.3 to 9.5 in). Its mass
is from 567 to 624 g (1.246 to 1.374 lb). The smaller women's ball's
circumference is between 724 and 737 mm (28.50 and 29.01 in), its
diameter 230 to 235 mm (9.07 to 9.23 in), and its mass from 510
to 567 g (1.123 to 1.246 lb).
Playing the Ball
The ball may be advanced toward the basket by being shot, passed,
thrown, tapped, rolled or dribbled. Passing is throwing the ball
from player to player. Dribbling is when a single player runs
while continuously bouncing the ball. The ball cannot be kicked
deliberately or struck with the fist, and must stay within the
Running with the ball without bouncing it,
or travelling is illegal; as is double dribbling, the act
of dribbling with
two hands or
starting a second dribble after having caught the ball after a
first one. A player's hand cannot pass the vertical while dribbling,
so that his hand is partially below the ball; this is known as
carrying the ball. In higher levels of basketball time limits are
imposed on advancing the ball past halfway, remaining in the restricted
area (also known as the "paint") and attempting a shot.
Rules with playing the ball are stricter in the NBA. Contrary to
popular belief, there is no limit to the amount of steps a player
can take between bounces while dribbling.
To interfere with the ball while on its downward flight for a
basket, or while it is bouncing on the basket, is called goal tending
and is a violation. Goal tending is one of the most complicated
calls of basketball, and is significantly different in international
An attempt to unfairly disadvantage an opponent with personal contact
is illegal and is called a foul. These are most commonly committed
by defensive players; however, they can be committed by offensive
players as well. Normal fouls are called personal fouls. Players
who are fouled either receive the ball to pass inbounds again,
or receive a free throw if they are fouled in the act of shooting.
One point is awarded for making a free throw, which is attempted
from a line 4.5 metres (15 feet) from the basket.
If a team surpasses a preset limit of team fouls in a given period
(4 in international and NBA games), the opposing team is awarded
free throws on all subsequent fouls for that period. Offensive
fouls and double fouls are not counted as team fouls in the NBA,
but they are in international games.
A player or coach who shows poor sportsmanship such as arguing
with a referee or fighting with another player can be charged with
a technical foul. A player or coach with two technical fouls is
disqualified from the game and is required to leave the stadium.
Blatant fouls with excessive contact or that are not an attempt
to play the ball are called unsportsmanlike fouls (or flagrant
fouls in the NBA) and incur a harsher penalty; in some rare cases
a disqualifying foul will require the player to leave the stadium.
If a player commits five fouls (including technical
fouls) in one game (six in some professional leagues, including
he is not allowed to participate for the rest of the game, and
is described as having "fouled out". If no substitutes
are available, the team must forfeit the game. Some leagues, including
the NBA, allow disqualified players to re-enter the game at the
cost of a technical foul on the team.
A team consists of five players and up to seven substitutes, though
in series where there are three games or less, only five substitutes
are allowed. Any number of player substitutions are allowed during
the game, although substitutes can only enter a game during a
stoppage of play.
Male players generally wear shorts and a sleeveless top, and high-top
sneakers that provide extra ankle support. Female players have
worn shirts and skirts in the past, but most female players now
wear uniforms identical to those worn by men.
A referee and one or two umpires control the game, these are the
officials. On the scorebench, there are table officials, responsible
for the administration of the game. The table officials include
the scorer, who keeps track of the score and fouls by each player,
the assistant scorer who controls the scoreboard, the timekeeper
and the shot clock operator.
Referees and umpires generally wear a grey shirt and black trousers.
These officials call fouls, award successful baskets, and so on.