I think that you are missing my point. I am not arguing that Shields has been pitching better than Porcello at this point of the season. My point is that Porcello is getting a lot of positive reviews of his performance and Shield has been doing poorly and getting criticism for it, but the difference is just not that big. Unless father time is claiming Shields, regression should reverse any numerical advantage that Porcello is enjoying.
IMO, they are both crap so far this season.