Joe Musgrove, Pittsburgh Pirates
ERA through April 30th: 1.54
ERA since May 1st: 6.98
The Pirates entered Wednesday’s action as a last-place team in the National League Central while boasting one of the Senior Circuit’s worst run differentials. Musgrove hasn’t necessarily been an asset in Pittsburgh’s efforts to compete following a strong April.
Through the season’s first month, he did a good job of limiting base runners (5.2% walk rate, 0.89 WHIP), suppressing home runs (0.26 HR/9), and stranding runners who did reach base (72.8%). None of those things have gone as well since the start of May — his 7.5% walk rate isn’t horrendous, but his 1.47 WHIP and 1.40 HR/9 are both big increases, while his 51.4% strand rate is obviously a huge decrease.
No wonder he’s giving up nearly seven runs per nine innings pitched over his last 38.2 frames. What’s interesting here, though, is the usage of his slider, curveball, and changeup have all taken a noticeable step back.
Musgrove’s usage rate for each offering has gone down at least three percentage points. This has happened despite them being the only pitches in his arsenal to produce an opponent wRC+ below 100 (they’re all below 75).