I don't think it quite works that way, myself. Nadal's numbers on clay are ridiculous, but even a slight decline opens up all kinds of doors for other players. He wasn't awful against Soderling, for example. A little flat, lacking in intensity, not getting the best depth on the ball – but he wasn't awful. He wasn't spraying unforced errors everywhere or incapable of moving and playing defense. He was a little flat against a redlining Soderling and so he went home. If he played a sub-par match like that against Thiem, I definitely wouldn't be surprised to see Thiem win. Nadal doesn't have to fall to 2015 levels to be beaten at the French.