if I recall it correctly, Paul tried to get Roger to switch to a larger frame head (Wilson) racket face but he wasn't successful. I give you credit Lubicy he has had a very positive effect on Roger's game . However, Paul did have success with Sampras and Federer..he knows his tennis..
I'm not saying he doesn't know the game.....what I question is his competitive mindset and his in-the-box thinking. No matter how you slice it Federer's record with Annacone was terrible. Fed had the worst stretch of his career against Nadal by far with Annacone as his coach (0-4 in 2013) including these doozies:
6-4, 6-2 loss to Nadal at 2013 Indian Wells
6-1, 6-3 loss to Nadal at 2013 Rome
5-7, 6-4, 6-3 loss to Nadal at 2013 Cincinatti
Fed even lost to Nadal at Cincinatti with Annacone as his coach!!!!! Yes, Cincinatti!!!
That is how bad a coach Annacone was for Federer.
He couldn't even get Federer to beat Nadal on by far Fed's best court after Wimbledon on the entire tour (aside from Dubai and Basel which aren't Masters events).