Its jarring watching him on the green stuff right after watching him obliterate everyone on the red stuff. It's like watching a guy in an alternate universe. What you notice most is when he's returning serve on grass, he generally needs you to misfire to break. He needs you to make mistakes. On clay you're basically at his mercy even when you're serving. The most curious thing to me is he's won Wimbledon multiple times yet since then has lost to this murderers row: Rosol, Darcis, Muller, Brown. It is hard to fathom how he's fallen off so badly on a surface he's actually won majors on.