2023 Projection Showdown — THE BAT vs Steamer Starting Pitcher K%, Part 2

Yesterday, I flipped my 2023 projection showdown, pitting THE BAT/THE BAT X projections against Steamer, to the pitching side. I began by comparing strikeout rate between the two systems, discussing those starting pitchers THE BAT is more bullish on. Let’s now find out who Steamer is more bullish on. It’s important to note that Steamer K% forecasts are higher on average than THE BAT’s, so the differences are higher than in yesterday’s article. That’s why relative projections are much more important when valuing players in your fantasy league than absolute projections.

This is a far more interesting group of pitchers than yesterday’s list gave us, as it’s not just a list of the top pitchers that Steamer is just a bit more conservative on.

Kodai Senga tops this list…by far. The former Japanese league pitcher signed a five-year contract with the Mets, posting a career 27.3% strikeout rate in Japan. Steamer is forecasting the highest strikeout rate among systems, while THE BAT is significantly more bearish than the other systems in every single metric. I’m not sure how each system calculates their foreign league translations, but it’s pretty clear that THE BAT does theirs far differently than Steamer and ZiPS! Strikeout rates are lower in Japan, so relative to the league, Senga’s Japanese league strikeout rates actually equate to a higher mark in MLB, but that’s ignoring the competition level. Still, it’s surprising to see THE BAT’s strikeout rate forecast as low as 21.8%, but it’s something to keep in mind if considering rostering Senga as a potential downside.

Dustin May returned last year after undergoing TJ surgery and while his fastball velocity was down a bit, it still remained elite. With such velocity, a strikeout rate breakout has been expected for a while, but he’s only posted a mark above 23% back in 2021 and that came over just 23 innings. It’s hard to get a sense of what he’s capable of over a full season, as you have to have faith that velocity will eventually translate into a high strikeout rate. Steamer has that faith, while THE BAT does not. The last two small samples proves that he is now able to generate swinging strikes, which is the first step, though last year it didn’t turn into strikeouts. I think that given the high upside, the chances he comes closer to Steamer is much higher than he settles in at THE BAT’s pessimistic forecast.

Chris Sale is another name coming off injury and he also recently underwent TJ surgery. But more recently, his injuries weren’t arm related, as he instead suffered a stress fracture in his rib and then broke his wrist. Though it came in just 5.2 innings innings, a rebound in fastball velocity was good to see last year. I don’t see any reason to project a 25.3% strikeout rate like THE BAT is, so once again, will side with Steamer’s projection.

Nick Martinez shuffled between the rotation and bullpen last year and all projection systems expect the same this season. However, the majority of his innings should come as a member of the Padres rotation. It appears that despite projecting more innings, Steamer is projecting him to pitch a higher percentage of his games as a reliever compared to THE BAT. So if that’s actually the case, it would make sense to project a higher strikeout rate. In his second go around of MLB after spending time pitching in Japan, he pushed his SwStk% into double digits thanks to increased velocity and an increased usage of his changeup. Projection systems using velocity and noting a pitch mix change would be more likely to project him to sustain his strikeout rate spike. So I’m siding with Steamer again here.

Brad Keller is in a similar boat as Martinez, shifting between the Royals rotation and their bullpen. Despite recording the highest average four-seam fastball velocity and SwStk% of his career, his strikeout rate declined from his 2021 spike and finished well below the league average. Steamer is projecting a strong bounce back, which would represent the second highest mark of his career. I have no idea why THE BAT is so pessimistic to project a new career low. I’m going to bet on the increased velocity eventually translating to a higher strikeout rate and again side with Steamer here.

Finally, we find 2022 rookie Graham Ashcraft, whose strikeout rate was underwhelming in his first year. To post just a mid-teen strikeout rate with a fastball, both a four-seamer and sinker, that averages over 97 MPH, is head-scratching. Only his slider generated a double digit SwStk%, and even that pitch was below average for the pitch type. I’d have to imagine there’s significant upside here and that the light could turn on at any moment. He has posted a mid-20% and mid-30% strikeout rates in the lower minors, so it’s not like he’s never been able to convert the velocity into whiffs. This is an easy call that Steamer’s strikeout rate proves closer and I think he’s a deep, deep sleeper in deeper leagues. In fact, along with a high GB%, I actually quite like the potential here.