The Relievers from Apokolips

This bizarre 2020 season has constantly been referred to as the start of a new decade for MLB. The previous decade, of 2010-19, gave to baseball a multitude of strikeout artists like had never been seen before. Five relievers had over 13 K/9 across 300 or more innings for the decade. But sadly, to paraphrase a controversial figure from a subject I disdain, the gods are dead, the gods remain dead, and time has killed them. And this is true, as those five pitchers are no longer the dominant figures they once were. Aroldis Chapman has a 5.20 FIP this season; Dellin Betances has pitched 11 innings the last two seasons combined; Craig Kimbrel has been below replacement each of the past two years; Andrew Miller no longer commands his pitches; and Kenley Jansen is still better than league average, though no longer exceptional. Fortunately for baseball fans, as Jack Kirby has written, when the old gods die, new gods rise. And 2020 has produced two strikeout deities who may be the most incredible of all in the right arms of James Karinchak and Devin Williams.

Looking at the MLB leaderboards for relief pitchers, these two names litter the top in many categories. In fact, entering Monday’s games, these were their respective ranks among qualified relievers in a few key categories:

What makes the two of them so special, however, is the fact that they are both doing this as rookies. Williams, at 53.4%, and Karinchak, at 48.8%, are currently running the highest strikeout rates ever for qualified rookies. Williams also has the best FIP- (23) of any rookie season in MLB history, while Karinchak (35) checks in at fifth. The urge to compare these incredible pitchers is natural. Unable to resist, and having been lent some clout from Pitching Ninja, I posted this Twitter poll in the early hours of Sunday morning:

After leaving the poll open for 24 hours and receiving 1,738 (no, I won’t be making a Fetty Wap joke) votes, Williams defeated Karinchak by 3.6%, or about 63 votes. Williams was the winner, but not by a huge margin. This margin certainly wasn’t wide enough to have answered the question for me. So I have decided to tackle it myself. At this precise moment in time, Devin Williams is a better pitcher than James Karinchak, and the denizens of Twitter say he will still be over the next three years. Yet those denizens don’t have my platform, and the final word is thus mine. Time for me to prognosticate.

Since he was deemed champion by the people, I will begin my examination with Williams. Up until the 2019 season, Williams had been used primarily as a starter, with high walk rates keeping his performance very middling. In 2019 he switched to the bullpen, and in 57 MiLB innings he had a 2.21 ERA with 82 K, though still 30 BB. Those walks continued to plague him in his 13.2 MLB innings in 2019, leading to a 4.82 FIP despite a good 9.22 K/9. Yet now in 2020 he is, on a rate basis, the best rookie pitcher of all-time. Clearly there has to be a reason for this.

Of the 254 MLB pitches thrown by Devin Williams in 2019, 99 of them were sinkers; those 99 sinkers produced an xwOBA of .434. Now, in 2020, only 8 of his 320 pitches have been sinkers. Instead, he has increased his changeup percentage from 36.6 and 54.1. His changeup is very, very good. Before I start discussing it, just take a look, as it is delightful to watch.

The average spin rate on Williams’s changeup is 2844 rpm, the highest in MLB on changeups by a wide margin. It also has the fifth most vertical drop and most horizontal movement of any changeup in baseball. Batters have hit it for a mere .091 xwOBA in 2020. This has allowed Williams to use his four seamer more effectively as well, with the Whiff% against it rising from 16.1 to 38.9, despite its velocity remaining exactly the same at 96.4 mph. While this fastball adds to his arsenal, make no mistake, it’s the impossible changeup (I think it’s actually a screwball) that is letting Williams be such a dominant pitcher.

The rise of James Karinchak is a very different story. While Williams’s emergence as a strikeout monster is unexpected, Karinchak’s was prophesied. In 30.1 IP across three levels of the minors in 2019, Karinchak struck out a mind boggling 74 batters, a rate of 22.0 per 9 innings. Even more impossible sounding was his K rate, 59.2%. Due to this season, ZiPS projected Karinchak to have the second highest K/9 in MLB in 2020, trailing only Josh Hader. Karinchak hasn’t disappointed.

Again, surely there is a reason why Karinchak is so good at missing bats. There are actually two. Karinchak throws his four seamer 46.1% of the time, at an average of 95.4 mph. Batters have a Whiff% of 34.9 against it, and a .211 xwOBA. This is attributable to the rise he gets on his fastball: 3.6 inches against average, good for 4th in baseball. The active spin on this pitch is also excellent, at 97.7%, 18th in MLB. Karinchak’s other weapon is his curve, a pitch that gets whiffs 56.7% of the time, despite only ranking 174th in spin. The vertical drop on this pitch is very mediocre, though the horizontal movement is quite good. But what makes him unhittable is how similar his release points for fastball and curveball are, and how well they tunnel. Observe:

These pitches look remarkably similar, until the curve drops and the four seamer appears to rise. This is why Karinchak is possibly the most fearsome strikeout force in the world.

Now, for comparing which of Karinchak and Williams I would pick to be in my bullpen for the next three seasons. The age factor favors Karinchak, but only slightly; he’s in his age-24 season and younger than Williams by exactly a year and a day. What truly does favor Karinchak, however, is that he has thrown far fewer pitches in his career, spending less time in the minors and switching to the bullpen sooner than Williams. While current performance is better for Williams, the track record heavily indicates that Karinchak is the better pitcher. To top it all off, as great as his changeup is, Williams relies on using a pitch that no one has seen before. It seems to me that it would be more likely for batters to adjust to this than they would to the guessing game Karinchak’s tunneling requires. Devin Williams has been historically great, and I will undoubtedly rate him in my top 5 relievers going into 2021. But for 2021-2023 – my apologies to the wisdom of the Twitter-verse – I’ll bet on James Karinchak.