Ivan Lendl (Czech pronunciation: [ˈɪvan ˈlɛndl̩]; born March 7, 1960) is a former world No. 1 professional tennis player and is currently coaching current world No. 1 Andy Murray, alongside Jamie Delgado. Originally from Czechoslovakia, he became a United States citizen in 1992. He was one of the game's most dominant players in the 1980s and remained a top competitor into the early 1990s. He has been described as one of the greatest tennis players of all time. Lendl's game relied particularly on strength and heavy topspin from the baseline and helped usher in the modern era of "power tennis".
Lendl captured eight Grand Slam singles titles. He competed in 19 Grand Slam singles finals, a record surpassed by Roger Federer in 2009, Rafael Nadal in 2014 and Novak Djokovic in 2016. He reached at least one Grand Slam final for 11 consecutive years, a record shared with Pete Sampras, with the male primacy of eight consecutive finals in a Grand Slam tournament (a record shared with Bill Tilden at the US Open). Before the formation of the ATP, Lendl reached a record 12 year-end championships (equalled by John McEnroe). He won two WCT Finals titles and five Masters Grand Prix titles, with the record of nine consecutive finals. He also won a record 22 Grand Prix Super Series titles (1980–89), the precursors to the current ATP Masters 1000.
Lendl first attained the world No. 1 ranking on February 28, 1983 and bolstered his claim to the top spot when he defeated John McEnroe in the 1984 French Open final. For much of the next five years, until August 1990, Lendl was the top-ranked player (with a break from September 1988 to January 1989 when Mats Wilander was at the top). He finished four years ranked as the world's top player (1985–1987 and 1989) and was ranked No. 1 for a total of 270 weeks and set a new record previously held by Jimmy Connors, since broken by Pete Sampras and Roger Federer. He is one of three male players in the Open Era (with Connors and Federer) to win more than 1,000 tennis singles matches (1,071). Lendl has won 94 singles titles, second only in the Open Era to Connors' 109 titles. Lendl has been runner-up in a record 11 Grand Slam finals.