If you’re in a deep league and your free agent pool is barren, now is a good time to start perusing the minor league leaderboards for potential callups who could earn positive fantasy value. Today, I’ll start with pitcher SwStk% leaders. In my non-scientific observations, a pitcher’s minor league SwStk% better correlates with his MLB strikeout rate. That means that if I see a high strikeout rate without a high SwStk% in the minors (such as a 30% strikeout rate, but only 11% SwStk%), I’m not optimistic the pitcher will post a strong strikeout rate in the Majors. On the other hand, if I see a high SwStk%, but mediocre strikeout rate, I think there’s more upside, and won’t shy away.
So let’s review the top 10 leaders in SwStk% across all of Triple-A. I used a 30 inning minimum.
A whifftastic showing at Triple-A to open the year earned Ryan Pepiot a promotion to the Majors in mid-May, when he made three starts for the Dodgers. The team’s fifth ranked prospect failed to carry over his ability to miss bats over a tiny sample and was returned to the minors. Oddly, his changeup graded out as an elite pitch, but only recorded a 5.1% SwStk%. Obviously, that’ll need to be better for any chance of MLB success, considering he only threw a cutter to go along with the change and his four-seamer.
Who would have guessed that César Valdez, the 37-year-old journeyman reliever, would be sitting in second place in SwStk%?! It’s still hard to believe that he opened last year as the Orioles closer and recorded eight saves. Also surprising that he has generated so many whiffs and yet still only posted a low 20% strikeout rate.
Félix Peña is now a free agent and another who couldn’t convert swinging strikes into a high strikeout rate.
Tucker Davidson’s control disappeared during his 15.1 innings with the Braves this year, but he’s been fantastic at Triple-A. His fastball velocity was also up this year. I wouldn’t give up on him in deep leagues, especially keepers.
Aaron Leasher doesn’t appear on any prospect lists and is yet another whose strikeout rate is well below what you would expect given the strong SwStk%. It’s hard to imagine he’s recalled anytime soon given his 5.27 ERA, but perhaps teams look past ERA by now and recognize the underlying skills and whiff ability. He seems like more of a wait and see though.
Finally, a real top prospect in Max Meyer! The third overall pick in the 2020 Amateur Draft, Meyer has posted a good, but not great, strikeout rate, despite a great SwStk% mark. He has posted an underwhelming 4.54 ERA, which might possibly be what’s delaying his promotion. It depends on how stat-savvy the Marlins organization is, of course — are they looking at ERA to make promotion decisions, or underlying skills? Meyers’ ERA is inflated by a low LOB%, which is almost assuredly a fluke. He should be recalled at some point and should at least deliver deeper league value.
Matt Krook isn’t much of a prospect and has endured major control problems his entire career. It’s too bad, because his whiff ability, plus ground ball tendency, would have made him intriguing.
Erich Uelmen is just a reliever who has also struggled with control. Nothing to see here.
Huascar Ynoa enjoyed a nice breakout last year before injury struck. However, his control has disappeared this season, though looking at his history, he’s struggled with control issues in the past as well. So this isn’t out of nowhere. His velocity remains good and he has still be generating the whiffs. If the Braves give him another chance in the rotation, he’s worth speculating on again in deeper leagues.
It’s too bad our third overall prospect Grayson Rodriguez suffered a strained lat and won’t return until September, if at all this season. While his SwStk% wasn’t quite as impressive as his strikeout rate, he was still dominant yet again. A 37.4% strikeout rate over 56 innings in Triple-A is insane! Sadly, we’ll likely have to wait until 2023 to see him in the Majors.