Use your other pitches, man
Wednesday night, Ian Kennedy gave up his seventh home run as a member of the Phillies in only his 16th appearance with the team. What’s most impressive about this home run is that it came on a fastball quite literally down the middle of the plate.
Giving up seven home runs in only 16 appearances is bad, but is also on the fluky side of things. Kennedy was quite bad in 2020, but if you want to chalk that up to small sample size (15 innings pitched) during a pandemic shortened season, I wouldn’t blame you. He was quite good with Texas this season, the reason the Phillies chose to acquire him in the first place along with Kyle Gibson.
We can discuss whether or not Kennedy should remain the closer a different time, but if the team is going to continue to use him the role, it might be better for him not to used as a one trick pony. It’s a trend that started this year while he was in Texas and has “worsened” since he came to Philadelphia. Perhaps it’s time to reverse course.
Take a look at this pitch usage map for Kennedy for his career.
Throughout his career, Kennedy has mixed up his arsenal with some combination of four pitches. Since he was a starter his whole career until 2019, it makes sense. You can’t rely on only two pitches if you want to make it through a lineup at least three times (coughSuarezcough). On the chart, you can see that since he became a full-time reliever, Kennedy has given up everything but the four-seam fastball, changeup and curveball. There have been attempts made at a cutter, but this season has seen that pitch almost get tossed by the wayside. What’s discouraging is the huge uptick on fastball usage and subsequent downturn in using anything else. It’s made him predictable as a pitcher and seems to have gotten worse since the trade.
Next, look at pitch usage for this season.
You can see that while with Texas, Kennedy was trending towards using mostly fastballs during his appearances. When traded to Philadelphia, he was back to mixing in other things, as seen by the drop in usage during August. Now that we have turned things back to September, Kennedy has gotten a taste of the “fastball only” elixir and seems to like it. The issue is that his fastball is starting to get pummeled.
If you’re a believer in the expected stats, Kennedy should be getting by much better than he has been these past few weeks. The xSLG and xWOBA numbers for September are way out of whack compared to what he’s actually given up. However, in August, as you can see, the pitch was starting to get hit harder more often, leading to bad results. Increasing the usage of it seems to be inefficient considering the results he had in August, where expected stats and actual stats were almost in sync with each other.
If the suggestion to simply “use your other pitches” and make that suggestion based on data, unfortunately, there isn’t much to go off of. Last year’s numbers for those pitches are all….not good. This year, he hasn’t used them enough to make firm statements about. For example, the pitch he used the most this year (changeup) has been used 8.9% of the time this year and only 68 time all season. The pitch calling of J.T. Realmuto also needs to be factored in, as, anecdotally at least, it has left much to be desired this year among all pitchers on the team.
However, with the performance being what it has been, the team should really be getting him to mix it up a little bit more. There isn’t a bit of evidence that his fastball is Chapman-esque and shouldn’t be featured to the extent it has been. Using his whole arsenal available to him needs to be an option that is on the table if he is to continue to close out games. It can’t hurt worse than it already has.