I hear Robert Lansdorp and Nick Bollettieri's name mentioned a lot. I believe Lansdorp coached Sampras, Davenport and Austin, among others, while Bolletieri I think coached Agassi, Sharapova, and Haas, among many others. But what kinds of techiniques and theories and grips and trends are each of these two men known for pioneering? I believe Bollettieri promoted such things as the swinging volley and inside-out forehand, but what else? Can someone who knows plenty about this topic give us all a nice summary of each coach's basic philosophies and approaches to tennis and how they might be similar or different from each other?