Premise: Xavier Malisse (born 19 July 1980) is Belgian retired professional tennis player. Born in the north-western Flemish city of Kortrijk and nicknamed "X-Man", he is only one of two players from Belgium (the other being David Goffin) to have been ranked in the top 20 of the ATP tour, with a career-high singles ranking of World No. 19.
Hypothesis: At one point, only 18 singles players were ranked higher than Malisse.