<Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> On NBA basketball courts the key is rectangular, with a restricted area arc nearest to the basket . In the NBA the half - circle nearest the basket's hash marks are displayed to facilitate jump balls in the free throw lane . </Td> <Td> On NCAA basketball courts the free throw circle's half nearest the basket's hash marks are not marked because there is no jump ball held in the free throw lane . </Td> <Td> In FIBA - affiliated leagues, courts such as the Nokia Arena had trapezoidal keys . Until 2003, the half circle was displayed, but many sponsors use that section of the arc for advertising . </Td> <Td> After the changes ordered by FIBA took effect on 2010, the Nokia Arena changed to rectangular keys, but the lines used to denote the 12 - foot boundary in NBA keys are not present; sponsors may use the inside arc for advertising in FIBA play . For Euroleague play, the half - circle is required since jump balls are conducted in the free throw lane (as of 2013). </Td> </Tr> <P> Originally, the key was narrower than it is today and had the shape of a keyhole, measuring six feet (1.8 m) wide, hence "the key", with the free - throw circle as the head, and the shaded lane as the body . It has been also called "cup" or "bottle" in other languages, because of how it looks from other perspectives . Due to the narrowness of the key, imposing centers, such as George Mikan, dominated the paint, scoring at will . To counter this, the key was widened into 12 feet (3.7 m) from 6 feet (1.8 m) at the onset of the 1951--52 NBA season . </P> <P> Men's professional basketball in the United States (notably the National Basketball Association) widened it further to 16 feet (4.9 m) in the 1964--65 NBA season to lessen the effectiveness of centers, especially Wilt Chamberlain . The NCAA retains the 12 ‐ foot key to this day . </P>

Why is it called the key in basketball
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