Who is a considered a better tennis player, Martina Navratilova or Jack Sock?
Martina Navratilova: Martina Navratilova (Czech: "Martina Navrátilová" ] ; born Martina Šubertová ] ; October 18, 1956) is a former Czechoslovak and later American tennis player and coach. Martina Navratilova:  In 2005, "Tennis" magazine selected her as the greatest female tennis player for the years 1965 through 2005 and she is considered one of the best, if not the best, female tennis players of all time. Jack Sock: Jack Sock (born September 24, 1992) is an American professional tennis player who is currently ranked world No. 21 in men's singles by the Association of Tennis Professionals (ATP).
Martina Navratilova