Ah, I can see you're a bit upset with my column, Don.
Hopefully you read the piece and not just the title, but I'd like to clarify a few things.
1) Most importantly, my conclusion read as follows:
Ultimately, Jake Arrieta’s disastrous pitching line from Saturday’s start was caused by a host of factors: bad luck, a less-than stellar breaking ball, questionable game-calling and an inability to execute in key situations. I won’t go so far as to assert how much of the blame should be doled out to Fox’s game-calling, but it does seem that Wieters is a bit more in tune with the nuances of his staff. Because of all these factors, we can expect a rebound for Arrieta in his next outing.
So, while I believe the game was called somewhat poorly, it was only one of several factors that led to Arrieta's early exit.
2) While you suggest that Arrieta was touched because he didn't mix in his pitches enough, the data actually suggest that he did not rely on the fastball enough. He threw the fastball 16% less in his second start and relied overly on the slider, which was inconsistent. Arrieta should take the blame for having a poor slider, but the battery need to hone in on what pith is working that night and shift the game plan. Arrieta needs to be able to shake off his catcher, no matter who it is, when he knows what pitch to throw. I agree wholeheartedly with you there.
3) While I believe the changeup can be a powerful weapon for Arrieta, he didn't throw it much more (4 times in 99 pitches) in his first start than he did (1 or 2 times in 77 pitches) in his second start. The only major change in pitch selection seems to be a shift from the fastball (which was very good) to the slider (which was less than).
Anyway, like usual, I respect the hell out of your opinion, Don, and I'm glad to have the conversation. It seems to me that we may have gotten off on the wrong foot in these forums, with some sharp differences in opinion on a couple of amateur draft candidates and now this. Ultimately, these things are minor in the long term.
What I want to make clear is that my column was not intended to come to any major conclusions about Fox and his effectiveness, but more so to play with pitch f/x data and see what it can tell us about pitch selection and effectiveness.