Reviewing the Rookie Pitchers — Through June 13, 2023

Let’s continue reviewing rookie starting pitchers with a dive into another group.

As someone who doesn’t really follow prospects, I was super duper confused when I read that Guardians’ top prospect Logan Allen was getting the call to make his MLB debut. Wait, Logan Allen? Didn’t he debut years ago, in like 2019?! Of course, this was a different Logan Allen, even though the original also throws left-handed and played for the Guardians, when they were still called the Indians. This Allen actually looks like a promising prospect, while the other is pitching in the Rockies’ minor league system.

Despite posting an absurd 6.49 ERA in 59.2 innings at Triple-A last year, all it took was a 1.26 mark over 14.1 innings and a 34.5% strikeout rate to convince the Guardians he was ready for his debut. Allen hadn’t posted a SwStk% below 14.2% in the minors throughout his career, which I love to see from a pitching prospect. So far in 51.2 MLB innings, he hasn’t been quite as impressive as in the minors, as his SwStk% has declined and strikeout rate has plummeted. He doesn’t exactly throw hard, as his four-seamer has averaged just 92 MPH, but the Guardians have featured a number of pitchers in the past and present who have strong enough secondary offerings to offset a mediocre fastball.

Though his fastball velocity is underwhelming, it’s been good enough to generate an above average 9.9% SwStk%. He even complements it with SwStk% marks over 15% on both his slider and splitter, so that’s a pretty solid three-pitch mix. In fact, I would argue there’s some additional strikeout rate upside here. Not significant, but I could definitely see something closer to 24%-25%. That could help offset potential regression as his HR/FB rate rises and LOB% falls more in line with the league average. I’m not a huge fan, but he should earn a bit of positive value in shallow leagues the rest of the way.

Guardians top prospects Allen and Tanner Bibee made their MLB debuts just three days apart, so I’m sure I wasn’t the only one debating which I liked better to bid more on with my FAAB. I think I ended up just bidding the same, failing to land either of them. Sure enough, the pair feature near identical strikeout and walk rates, though Allen’s SIERA suggests he has been a bit better than Bibee.

While Allen spent an extra year in the minors, Bibee rocketed through, making his pro debut just last year and already reaching the Majors in April. Aside from a control lapse over a small sample at Triple-A this year, Bibee has shown excellent control in the minors, and similar whiff-inducing ability. He’s a fly ball pitcher, though, which could result in gopheritis, but he has been able to curb that issue as his HR/FB rate sits well below the league average. I’m not sure how sustainable that is though, so there’s a good chance he starts allowing a higher rate of home runs.

He throws much harder than Allen, averaging 95.3 with his four-seamer, but he hasn’t induced nearly the rate of swinging strikes as his rotation mate. That’s because his four-seamer’s SwStk% sits at just 5.9%, which is below the league average, while his second most used pitch, his slider, has come in at just 11.9%, also below the pitch’s average. His changeup has been excellent though at a 17.3% SwStk%, while his curveball has been exceptionally weak at a 5.5%. With the high velocity fastball, you would think there’s upside to generate a higher whiff rate.

For now, given the effectiveness of each pitcher’s pitches, I would prefer Allen in the short-term. However, with a higher velocity fastball, it’s possible than Bibee ultimately has the higher upside, if he could convert that velocity into more whiffs.

Bryce Miller was ranked as the 72nd best overall prospect, which must have been the reason why the Mariners felt he was worthy of promoting straight from Double-A this year, despite an ugly 6.41 ERA over 19.2 innings. Seriously, Miller skipped Triple-A, even though he didn’t even succeed in four starts at Double-A. Surprisingly, to say the least! However, he was much better at the level in 2022, where he posted a strikeout rate of nearly 30% and a 13.1% SwStk%, en route to a more palatable 3.20 ERA.

Though 19.2 Triple-A innings this year is tiny, I still was skeptical given his underwhelming 21.2% strikeout rate and mediocre 11.6% SwStk%. While the excitement of another top prospect getting the call increased his FAAB cost, I wasn’t rushing out to pick him up. I looked pretty silly after his first five starts, as he had allowed just four runs, including three of which he didn’t allow any. He then allowed a combined 15 runs in the next two starts as his BABIP luck ran out, and he finally started allowing home runs. On the season, his strikeout rate and SwStk% mark are unimpressive, and particularly his 24.4% CSW%.

My concern here is his reliance on his fastball, which he has thrown 69.2% of the time. Sure, it has averaged 95.1 MPH, and generated a better than average 11.3% SwStk%, but none of his other pitches have been any good at generating whiffs. In fact, his best secondary pitch has been his least used curveball at 9.1%, then it falls to just 7.4% for his slider. He has thrown 37 changeups and not one of them has resulted in a swing and miss! A great fastball is the best pitch to build off of, but it appears that his secondary stuff is severely lacking. The light bulb could go on at any time, of course, but he’s got a long ways to go given the low SwStk% marks each currently have.

His high fly ball rate could help him keep a better than average BABIP, but could lead to home run issues if/when that HR/FB rate jumps into double digits. I’m not particularly excited here given the current underlying skills, but I reserve the right to change my opinion if his secondaries become more whifftastic!

Despite being 28 years old, J.P. France still managed to make the Astros’ top prospect list, ranking 12th. He’s had some impressive strikeout rates in the minors, but they are likely inflated by his flipping between the rotation and bullpen. He has never posted a SwStk% below 12.8%, which is good. But again, he has never pitched at one level in a season where he only started. So it’s tough to gauge his potential as a starter without having those splits.

So far, he has flashed average fastball velocity, but has complemented the pitch with an array of offerings, almost completely filling up the Pitch Type section. While his four-seamer has been below average at generating whiffs, all of his other pitches have been at least average to above average. In fact, three of his four secondary pitches sport double digit SwStk%. I fully expected to check his pitch splits and see at least one pitch with awful results, suggesting he should ditch it. But that hasn’t been the case.

The elephant in the room here is his historical control. He has posted double digit walk rates nearly everywhere he’s pitched, but has managed to post a professional best mark so far in the Majors at an acceptable 8.8%. Of course, that comes with his worst strikeout rate by far, even though he has generated a high rate of called strikes for a very solid 29.6% CSW%.

Overall, both SIERA and xERA consider him quite fortunate to have posted a sub-4.00 ERA so far and his strikeouts aren’t helping anyone. If the walk rate increases like his history suggests, that down strikeout rate is going to be a major issue. I would be nervous of some major regression moving forward if I were an owner.