maybe not on clay or grass but it's safe to say that for now both james blake and andy murray are both hard court specialist
not long ago and still to this day the likes of Hewitt and Roddick;Blake still about about clay court specialists as an insult;guess it's safe to say that those who grew up on clay:Federer and Nadal are the ones winning the majors
and not the hard court specialists
the last slam winner grew up on clay too
the 21 century player is shaping out to play well in all 4 majors thus means clay;hard courts and grass unless you're Blake
Djokovic, Del Potro, Davydenko, Soderling, Murray, Tsonga, Simon, Verdasco, Berdych, Blake, Haas, Gonzalez (debatable, maybe clay), Cilic.. all these players are at the best on hard courts.
Federer and Roddick are grass, Nadal is clay.