Nadal was #2 in the world at 18 years old. Went pro at 15. Guy has so much mileage on him now and the way he has to grind out points, just dunno especially as the draws start to get tougher for him. Grass is worst surface and hard court leads to his knee problems. I still remember in 2005 as he was unheard of unless you are a hardcore tennis guy how he swept through the entire clay season as a 17/18 year old. Won Monte Carlo, Rome, Barcelona, and a couple smaller clay court tourneys before winning the French.Went from around 50 in the world to #2 in the span of a couple months.