Premise: 1978 US Open (tennis) . It was also the first time the tournament was played on hard courts , as opposed to much of its history on grass and a brief stint , from 1975 through 1977 , on clay . Tennis . Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent 's court . During most of the 19th century , in fact , the term `` tennis '' referred to real tennis , not lawn tennis : for example , in Disraeli 's novel Sybil ( 1845 ) , Lord Eugene De Vere announces that he will `` go down to Hampton Court and play tennis . '' The four Grand Slam tournaments ( also referred to as the `` Majors '' ) are especially popular : the Australian Open played on hard courts , the French Open played on red clay courts , Wimbledon played on grass courts , and the US Open played also on hard courts .
Hypothesis: Tennis is not played on courts.
Label: CONTRADICTION