Jack Flaherty’s Best Pitch Has Been Underwhelming
Jack Flaherty has a 2.83 ERA through seven starts, which comes out to a 73 ERA-. His park adjusted FIP- of 75 is right in line with that figure; his FIP is 3.03. It would be easy to stop there and say Flaherty has been great; his excellent ERA matches up with his FIP, so he must be doing something right. Dig a little deeper, however, and there are some reasons to be skeptical. His overall line has been buoyed by a 7.5% HR/FB. His strikeout rate is down almost four percentage points compared to his last three seasons combined (25.8% versus 29.7%). Worse, his swinging strike rate is down to a below league-average 11.6%, indicating he has been somewhat fortunate to punch out a little over a quarter of the batters he has faced. On contact, things are not much better. His groundball rate is five percentage points lower than it was over those same three seasons and after allowing a below average rate of hard-hit balls from 2018-20, he is now right at league average.
This is all to say that Flaherty hasn’t quite been his excellent, arguably ace-level self (no, I will not be debating the definition of an ace). Poking around, I found an interesting trend. Flaherty has always leaned on his four-seamer and slider, but in 2021, that reliance has accelerated. He is throwing his fastball and slider as a higher percentage of his total pitches than in any other season up until this point. He is increasingly becoming a two-pitch pitcher:
There are two ways you can look at this. First, you could say that he is using his best offerings more often than ever, which can be construed as a positive development. Or you can say that this is making him more predictable, allowing batters to sit on those two pitches, making him less effective. Given that his peripherals are a bit worse this year, one might say that the latter explanation rings true. But his results are as good as ever, so maybe the former point is viable. Read the rest of this entry »