Collette Calls: A Game of Adjustments

If you heard me on SiriusXM over the weekend discussing my last article on Pete Crow-Armstrong, I mentioned how baseball is a continual game of adjustments. Hitters make changes to adapt to what pitchers are feeding them, and pitchers then adjust to the new version of those batters. Pitchers continue to have the advantage in the generic matchup, some more than others. It is a fact no hitter can cover everything a pitcher throws his way. They can study the pitcher to learn more about what he throws, how hard he throws each pitch, and that pitchers' tendencies when he is up, even, or behind in the count. This, in fact, is all publicly available data on a variety of sites. Even with the advantage of available information, hitting is still the most diffucult thing to do in sports. 

This game of perpetual chess can even happen within the season itself. We will sometimes see batters make changes within a season in efforts to break out of a slump. We saw Miguel Vargas do just that back in April, changing his fortunes for the better:

More infamously, we saw Cal Raleigh open the season with a normal bat, only to proceed to switch to a torpedo bat while hitting lefty, and then later using it from both sides of the plate as he continues to mash the ball this season. Honestly, it's tough to look for these changes in stances and swings without watching games or highlights regularly, because we don't have easy data which give us indications of changes. The Batting Stance Leaderboard at Baseball Savant only shows year over year changes, and one would need some datascraping skills to put together a database showing changes on that board. This is why I prefer to look at changes in pitchers, because it's much easier to find whether someone has shifted on the mound, added a new pitch, shelved an old pitch, or started throwing with increased or decreased velocity. 

I had this article idea mapped out in outline form to discuss some other pitchers but came across this great piece by Daniel Epstein at BaseballProspectus on the changes which have turned Kumar Rocker into something usable these days after a disastrous start to the season. Rocker was most recently recalled June 14 to replace the injured Tyler Mahle in the rotation, and he has taken advantage of two softer matchups with wins against the White Sox and Pirates, striking out 10 and walking four in 10.1 innings while allowing two earned runs. That got me thinking about some other pitchers who have made some adjustments in-season. 

Charlie Morton pitched his way out of a rotation spot after an utterly disastrous month of April which saw him finish with a 9.45 ERA and a 2.18 WHIP. Morton was demoted to the pen before moving back into the rotation in late May. In his last five starts, he's gone 4-0 with a 2.42 ERA, a 1.35 WHIP, a 30.1 percent strikeout rate and a 23.0 percent K-BB%. Morton took the demotion to the pen like a vet and has reworked his repertoire. Morton has reduced his ineffective cutter by 50 percent while leaning into his best pitch: the curve. His curveball usage has jumped to 43.2 percent from 34.2 percent in April and 38.4 percent in May. Morton's curveball has always been his best overall pitch with all his spin, but it wasn't performing like he needed it to in April. He has that pitch back and is leaning into it along with his four-seamer. Neither pitch has allowed a homer in this current run, and in fact, Morton hasn't allowed any homers since returning to the rotation:

Jose Soriano got off to a slow start in June with an ugly outing at Boston but has since turned it around with 28 strikeouts and just two earned runs in 20.2 innings of work in a three-start stretch against the Athletics, Yankees and Astros. Soriano was throwing a splitter more frequently in April and May but has nearly eliminated his use of the pitch here in June, instead leaning on his slider as his preferred tertiary offering. The combination of his knuckle-curve and slider are each generating whiff rate over 50 percent:

Even as I was authoring this piece, Edwin Diaz decided to try something new. Diaz's numbers are still quite gaudy, as he's striking out 37.5 percent of the batters he's facing and holding the league to a .162 average, and yet in the current stretch of the Mets now losing nine of their last 10 games, Diaz unveiled a pitch he had not yet thrown this season — and even the pitching data experts aren't sure what this is:

Diaz has thrown nothing but fastballs and sliders since 2021 and yet he chose that moment to throw something that Savant calls a changeup, but also came in at 94.5 MPH with no fade. Whatever it is, it's just the eighth non-fastball or slider that Diaz has ever thrown in his major-league career. It was an unusual time to see a new pitch, and credit to Olson who stayed on the ball and slapped it through the right side for a single. Perhaps it's a one and done pitch, but perhaps it's not and a nasty reliever just got a bit nastier, assuming he can get that pitch where he wants it.

Drew Rasmussen similiarly doesn't exactly need more help this season. He is 6-5 through 15 starts with a 2.61 ERA and a 0.97 WHIP and has held the league to a .208 batting average. His recipe of success has been quite simple: fastballs up and down while using cutters and sweepers to get to the edges. He tends to front-door his sinker to lefties and work the cutter to both sides of the plate, but then he showed up to Citi Field last week and threw six changeups. 

That's notable because he had not thrown a changeup since 2021, and that version of the changeup was a terrible one that got little swing and miss. He had the surprised Mets swing and miss at three of the six he threw them. They all went to lefties, who have hit .243 off him, including five of his eight homers he's allowed, compared to the .170 the righties have hit against him. In short, you have to love to see the process improvement within a season for someone who was already successful, with Rasmussen proactively addressing a concern in his splits by bringing in something new. Lefties now have to look for six different pitch types from Rasmussen when they come to the plate, and this new changeup has much less spin on it than his previous efforts, giving the pitch more time to alter its path on its way to the plate:

Conversely, his teammate, Shane Baz, needed to make a change. Baz came into New York that same weekend having allowed five or more earned runs in four of his previous 13 starts and was pitching to a 4.97 ERA and a 1.34 WHIP while opponents hit .255 against him. The day after Rasmussen rolled out his new changeup, Baz went out there and threw the first cutters of his major-league career. He threw the cutter 19 times against the Mets and 40 times in his most recent start against Detroit. If not for a hanging changeup to Riley Greene which became a three-run homer, Baz's second game with the cutter would have looked better.

The reason the cutter made an appearance is because Baz's slider needed the hook to be pulled off stage. The slider has been a terrible pitch for Baz this season, one which he has struggled to command for whatever reason and has often found the heart of the plate where the league has made him pay for that mistake. Six of his 14 homers this year have come off a pitch he has thrown just 82 times this season:

Rays pitching coach Kyle Snyder had to come up with something to change Baz's course this season, and the cutter may be just what the doctor ordered to get Baz on a better track moving forward, because he has looked more like his pre-TJ self in his last two starts even with the mixed results in the box score.

There may be more pitchers out there making these changes, but we don't have an easy way of seeing them without watching the games. These are five who grabbed my attention as I either watched the games on TV, or in the case of Morton, live in person. These changes don't guarantee any future success, but I am more impressed by veterans being willing to make adjustments within season, especially Rasmussen and Diaz, who were already enjoying solid seasons. As you watch games, be on the lookout for anything looking different with hitters or pitchers and then dive into the numbers to see what may be driving those changes and how actionable it may be for your fantasy roster moving forward.