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. In 1984, he recorded the best single season win-loss record in the Open Era at 96.47% (82/3). In 1981, 1983 and 1984 McEnroe was the ITF World Champion for Men's singles. He was also named as the ATP player of the year in 1981, 1983 and 1984. McEnroe is often rated among the greatest tennis players of all time, especially for his touch on the volley.[a]