On April 26th, I wrote the following on Randy Wolf:
What’s different? It’s hard to say. It certainly doesn’t hurt that his last three opponents were the Pirates, the Phillies, and the Astros, three weak lineups (Philly isn’t as bad as the others, but they’re also nowhere near as good as recent years). The biggest difference in his repertoire appears to be increased use of the slider — 20 times over the last four starts as opposed to only twice in the first two. Wolf has recorded outs with the slider so far, as evidenced by his +1.0 pitch type value on FanGraphs. However, he’s unlikely to keep doing so if the pitch can only draw 5% whiffs.
Right now, batters are fouling off the pitch 35% of the time, a major factor behind the pitch’s 70% strike rate. Something’s going to have to give here — either Wolf will have to throw the slider out of the zone, resulting in more walks, or the slider will stay in the zone and be put in play instead of fouled off. Regardless of how things even out, Wolf won’t be able to keep up this torrid pace.
Since April 26th, Wolf has put up a 3.52 ERA with a 36:18 K:BB ratio in 53 innings. The effectiveness of his slider, however, has waned considerably. The pitch’s value according to FanGraphs has dropped all the way from plus-1.0 to minus-3.6, a steep drop considering he has only employed the slider 176 times in this span.
As I predicted, Wolf couldn’t maintain his off-the-charts 70% strike rate with his slider. Since that time, his strike rate with the slider has fallen to 60%, a slightly below average mark. He’s still inducing a decent amount of foul balls with it, but that seems to be at the expense of whiffs (only 8%, still well below league average) than anything else.
Luckily for Wolf, his fastball and curveball have been excellent. Despite his relative lack of velocity, his fastball has been worth plus-3.8 runs on the season, nearing his pre-Brewers rates. He’s also thrown his curveball a bit more than previous years, and it’s been successful: plus-1.4 runs against average in about 241 pitches.
Wolf’s return to his old form has been an excellent sign for the Brewers, even if it hasn’t been turning into wins due to low run support — the team has been shut out in three of Wolf’s last nine starts. Thanks to the additions of Zack Greinke and Shaun Marcum, the club is now able to get this kind of production from their fourth starter. He’s no Cole Hamels, but right now not too many teams can boast a better fourth starting pitcher than Randy Wolf.