It only makes sense if one looks at it though an overly simplistic "player suddenly got a lot better, something funny might be going on" perspective. Jake didn't get much bigger, didn't start throwing harder, nor did his pitches start moving more. If you dig into the reasons for the improvement, there are numerous mechanical changes he's made since coming over that help explain why he's become so good. He's probably in better shape than he used to be, but certainly no more than his legendary workout regimen and diet would easily account for. It's actually for that reason that it would shock me if Jake got busted. I just don't see the kale munching, carrot and turmeric smoothie drinking Arrieta putting steroids into his body. I know people like him, and they absolutely refuse to use anything that might "contaminate" them in any way.