What impressed me is that he was able to generate pace (in a lot of cases) and put some heavy spin on the ball (not so often, but still). That he had a vicious slice I already knew, but now he seems to be able to use the very fast racquet movement he has in most shots. I think this style of play is very taxing, but if (and that is a big if) he maintains this level, he can go deep in the clay masters.