2023 Projection Showdown — THE BAT vs Steamer Starting Pitcher K%, Part 1

At last, we have completed our 2023 hitter projection showdown pitting THE BAT X against Steamer in various categories. Let’s now jump over to starting pitcher. I’ll start by comparing K% forecasts. THE BAT X only projects hitters, so I’ve switched over to the original THE BAT system to compare with Steamer. Let’s see which starting pitchers (defined as starting at least 75% of total games appeared in, and also using a minimum of 100 projected innings) THE BAT is more bullish on for strikeout rate.

Wow, this is a pretty darn good list of starting pitchers!

It’s pretty odd seeing future Hall of Famer and veteran Clayton Kershaw topping the list, and by a significant margin. THE BAT is more bullish on Kershaw’s strikeout rate, while Steamer is most bearish among all systems. Even though THE BAT is most bullish among systems, it still represents a decline from his previous three season marks. Steamer’s forecast is even more pessimistic, as it represents his lowest K% since 2018, and his second lowest mark since all the way back in 2010. Kershaw’s fastball velocity has sat below 91 MPH in three of the past for seasons, after it tumbled in 2018 and he hasn’t been able to regain it. So far, his slider and curveball have been strong enough to keep his strikeout rate in the upper 20% range. How much longer could he maintain that strikeout rate though with such underwhelming velocity? Will the velocity take another step down as he enters his age 35 season? It’s anyone’s guess, but it’s hard to believe his strikeout rate plummeted to close to Steamer’s projection. THE BAT may prove too optimistic, but I’d say he finishes closer to that forecast.

Tyler Anderson lucked his way into a sub-3.00 ERA last year, so his strikeout rate is important if his ratios dramatically regress. Once again, THE BAT is most bullish, while Steamer is most bearish among systems. Anderson has had an interesting strikeout rate history, posting marks above 20% during his first four seasons, then suffering a decline t just 15.8% in 2020, before rebounding to the 19%-20% range over the past two seasons. He sure does generate a solid enough SwStk% to think he’s capable of better strikeout rates, though a drop to a sub-91 MPH fastball velocity could be behind his decline. Since his velocity has stabilized, I see no reason to project the second lowest strikeout rate of his career like Steamer and side again with THE BAT’S forecast.

The ageless Justin Verlander suffered a meaningful drop in strikeout rate last year after a renaissance in 2018 and 2019, before undergoing TJ surgery in 2020. The strikeout rate decline mattered little, as he still managed to post a career low ERA, en route to a Cy Young award win. Amazingly, his fastball velocity has been as stable as it gets since 2017, after he experienced a dip from 2012 to 2016. It’s really incredible for the now 40-year-old. At some point, age has to catch up, right, RIGHT?! This time, it’s THE BAT out on its own bull island, as it’s the only system projecting a K% over 28%. Steamer, on the other hand, is in line with the rest of the systems. It looks pretty clear that his 2018 and 2019 marks in the mid-30% range were the outliers, so there’s little reason for me to believe that he’s going to increase his mark this season. I’m going with Steamer this time.

Next up is another start veteran and possible Hall of Famer, depending on his health, in Jacob deGrom. Somehow, he has posted strikeout rates over 40% over partial seasons the last two years, which is just unbelievable. And his last three year velocity has hovered around 99 MPH! This from a guy who debuted averaging just 94.5 MPH with his fastball. What mortal human gains 4.5 MPH on their fastball?! Amazing. It really doesn’t matter whether he posts a mark closer to THE BAT or Steamer’s forecast, as it’s likely to lead baseball’s starting pitchers either way. At age 34, you had to imagine some sort of decline, whether it’s velocity, spin rate, movement, or something will start affecting his performance. I think the percentage play is to assume the more pessimistic Steamer proves closer here, but deGrom hasn’t followed the percentage play at any time in his career.

From shuffling between the rotation and bullpen to mostly a starter, Cristian Javier enjoyed a true breakout last year with a pretty unique skill set. It’s pretty amazing how good his fastball has been considering it only averaged 93.9 MPH last year. That’s what happens when you throw it high in the zone and it has enough velocity to not get clubbed. It allows an extreme fly ball rate, but also generates lots of swings and misses. Also surprisingly, his slider has been good, but not elite at generating whiffs. So just by looking at his pitch type SwStk% marks, you wouldn’t come away thinking this was an elite strikeout pitcher. Here, THE BAT is in the middle of the systems in K% forecast, while Steamer is way at the bottom, a full percentage point below the next lowest mark, which is THE BAT. Given his history, I kind of have to think THE BAT proves closer, but I’m not totally sure how he has been this good.

My gosh Andrew Heaney, where did that come from?! As usual, he battled injury again and only ended up throwing 72.2 innings, but man were those elite innings. The explanation was a new slider he introduced and threw 32% of the time, at the expense of most of his changeup usage and all of his curveball usage. That slider was a killer, generating an elite 24.1% SwStk%. He also gained velocity on his four-seamer, recording a career high mark, a full mile per hour higher than in 2021. Projection systems aren’t typically aware of pitch mix changes, only velocity increased or decreases. While you never know how hitters may adjust during a second or third look this year, I’m going to go with THE BAT as proving closer. Of course, some of this depends on whether he could maintain his velocity spike and whether he’ll continue throwing that new slider at a similar frequency.