Premise: John Patrick McEnroe Jr. ( born February 16 , 1959 ) is an American former World No. 1 professional tennis player , often rated among the greatest players of all time in the sport , especially for his touch on the volley . McEnroe is known for his shot-making artistry and volleying skills ; for his rivalries with Björn Borg , Jimmy Connors and Ivan Lendl ; and for his confrontational on-court behavior , which frequently landed him in trouble with umpires and tennis authorities .
Hypothesis: John McEnroe is unknown.
Label: CONTRADICTION