If you're not top 20 as a teenager, you won't win multiple majors.
Of the 18 multiple majors winners who were teens in the ATP era,
-12 of them made the top 20 as teens
-Another 4 did it at the age of 20 (Kuerten, Kafelnikov, Safin, and Bruguera)
-Only Pat Rafter won multiple majors, but did not make the top 20 until he was 21 years old.
(and I can't find ranking info on Johan Kriek)
Making the year-end top 20 as a teen doesn't necessarily mean you will win a major tournament, but it is a good indicator.
Of the 22 men who made the year-end top 20 as teens, 5 retired without winning a major. 10 of them won multiple majors. 4 of them won just one major.
Good news for Gasquet, Djokovic, and Murray, who could all use some good news this week.
avatar by J'torian