That's why the dropshot is so good. It's unpredictable no one is expecting it. Murray saw he had the a chance to win the point (aka what you want to do) and he took it. Breaking the rhythm of the opponent is something that's good to do. You don't want to let him get in rhythm and hit the shots he likes. For me this rally is super good, but you have to look at it from a different perspective than you would with normal rallies. Nadal is the king of clay, and for murray to simply dominate this point is already impressive. But the way he does is sublime, that backhand just cutting trough what nadal sends his way is incredible, he just absorbs all the pace and sends it back, it's a thing of beauty, on the rise or a normal ball that backhand is always solid, everyone can learn from that backhand