Welcome to Mixing It Up, a weekly column where I look at starting pitchers who are making noteworthy changes to their pitch mix or pitch shape/velocity. We often assume that the offseason is the only time that pitchers will make meaningful changes to their repertoire or their pitch shape. While it’s certainly a time when the most tweaking happens, there are many pitchers who continue to modify their pitch mix or their grip as the season progresses in the hopes of capitalizing on the results or pitch modeling they’re seeing.
In this column, I’ll break down three to five pitchers each week who have shown a change in their profile that has me intrigued. It won’t always be a pitcher who requires an immediate add but could be somebody who has worked his way onto our fantasy baseball radars or a pitcher I think is set to begin a productive stretch. I’ll always try to make sure we have enough of a sample size to work with and I’ll be mixing in both shallow and deep league targets, so there should be a little something for everyone.
In the last couple of weeks we identified some positive changes in Luis Medina , Steven Matz and Freddy Peralta , but we also shone a spotlight on Chase Silseth , who lost his chance at a rotation spot for the Angels after their recent trades but then maybe gained it back with his effort last night in a spot start.
With that said, let’s dig in to this week’s pitchers of note.
Sandy Alcantara - Miami Marlins
Sandy Alcantara is clearly trying to find himself. After winning the NL Cy Young last year on the back of a season where he had a 2.28 ERA over 228.2 innings with a 17.7% K-BB%, the Marlins starter has disappointed with a 4.46 ERA and 13.5 K-BB% through 135.1 innings this year.
Some regression should have been expected after last year since Alcantara sported a 3.29 xFIP and 3.42 SIERA in 2022 to go along with his 2.28 ERA. The banning of the shift and the Marlins deciding to use Joey Wendle and Luis Arraez in their middle infield were always going to hurt a pitcher with a career 50% groundball rate, but I’m not sure anybody expected a year as poor as this.
Alcantara also seems to be looking for answers, which is the only explanation for why the right-hander decided to change his slider in the middle of the season and then change it back. As you can see in the chart below from Brooks Baseball, after pitching to a 5.04 ERA in March and April, Alcantara dialed back on the velocity of his slider, opting to add vertical movement.
The move didn’t work.
Alcantara posted a 4.85 ERA in May and a 4.59 ERA in June. What’s more, his slider had a 0.14 dERA and 23.9% swinging strike rate (SwStr%) in March/April but just a 4.05 dERA and 12% SwStr% in May and 3.77 dERA and 16.5% SwStr% in June. The pitch was never really a problem for him to begin with, so it’s odd that he chose to change the pitch mid-season, but anytime you see a veteran pitcher take two miles per hour off of a pitch while adding multiple inches of break, it’s not random small sample variation.
In July, Alcantara seemed to go back to his early-season slider, throwing it 90.4 mph again with just five inches of break and no horizontal movement. The pitch had a 1.34 dERA and a 20.2% SwStr% in the month and was, once again, his best pitch.
Now, the overall results weren’t elite, but Alcantara did pitch to a 3.31 ERA in July with a 17.85 K-BB%, so I think we can say at the harder slider is the better choice for him. In fact, as I’ve been saying for a few years, I think he can actually throw the pitch more as he used it just 21% of the time in July and only 19% of the time in two-strike counts.
The bigger issue for Alcantara appears to be his command. In June, his four-seam fastball got pummeled to a 10.95 dERA and 12.5% barrel rate, but in July, his change-up got hit hard to a 8.42 dERA and 9.75 barrel rate. He simply hasn’t had a feel for his whole arsenal at once this season, and you have to assume that some of it could simply be fatigue. Even if his arm isn’t hurting, fatigue can lead to mechanical inconsistencies which impact location. Alcantara threw over 432 innings combined in 2021 and 2022, so it’s possible that he’s just not as precise this season under the strain of that kind of work load.
What we do know is that Alcantara is back throwing his best pitch in the most effective way possible, and that’s only good news for his rest of season value. I just don’t think you’re going to all of the sudden get two months of Cy Young caliber pitching.
Brandon Pfaadt - Arizona Diamondbacks
When Spring Training ended, there was seemingly no more unjust decision than the Diamondbacks choice to keep Brandon Pfaadt in the minor leagues. Twitter was lit up in fury that Arizona didn’t think the right-hander was good enough to be in their rotation.
Now, it’s August and the decision seems to have a lot more sense.
The 24-year-old was fine in Triple-A, posting a 3.71 ERA and 27.1% strikeout rate, but he also allowed 1.63 home runs per nine innings. In his eight MLB starts, things have been even worse. Pfaadt has posted an 8.20 ERA, 5.00 SIERA, 11.1% K-BB%, 1.63 WHIP, and egregious 3.13 HR/9.
A big reason for Pfaadt’s struggles has been that his fastball is incredibly hittable. On the season, it has allowed a .382 average, .750 SLG and 11.7% barrel rate, while posting an 8.13 dERA and seven home runs allowed. So, it should be good news that Pfaadt has been using the pitch less of late, right?
Well, not really because the home runs allowed are the only reason the four-seam is worse than his sinker, which has allowed a .375 average, .750 SLG, 25% barrel rate, and a 10.00 dERA. The recent addition of the sinker and subsequent decline of the four-seam doesn’t seem to fix many of the concerns about Pfaadt, except that he may give up slightly fewer home runs on the sinker.
Yet, he has still given up three home runs on the four-seam in just his last two starts, so even limited usage, it continues to get his hard. In fact, the only two pitches that have worked for Pfaadt at the MLB level are his sweeper and his curveball. The sweeper has a .188 average against, .417 SLG, and 17.2% SwStr%, while the curve has allowed a .250 average, .250 SLG, and posted a 15.2% SwStr% in much more limited usage.
While it’s noteworthy that Pfaadt has seen the issues with his four-seam and is trying to address it, right now he’s just a one-pitch pitcher with a potentially solid curveball that he doesn’t really throw. There is a lot of work that needs to be done before I can buy in here for fantasy.
Hayden Wesneski - Chicago Cubs
Speaking of Spring Training, Hayden Wesneski was one of the most common “sleepers” heading into the season. The former Yankees prospect had a wicked sweeper and a deep enough array of pitches in his arsenal than he seemed like a good bet to win a spot in the Cubs rotation and produce solid swing-and-miss numbers.
That also hasn’t panned out as the 25-year-old posted a 5.51 ERA as a starter with 40 strikeouts in 49 innings while allowing 14 home runs and a .266 average. The Cubs moved him to the bullpen where he was able to lean on his slider more and post a 1.98 ERA and .188 average allowed in 13.2 innings.
Perhaps the Cubs saw an avenue for him to become a relief ace like Adbert Alzolay, who also relied on a vicious slider. However, the team may not be so quick to make that adjustment as Wesneski was tasked with starting on Friday and showed off some clear adjustments.
Here is his release point up until his demotion to Triple-A on July 2nd.
Now, here is his release point in his outing on Friday.
Even without specific numbers attached to it, you can see that Wesneski has a higher arm slot in his most recent start, particularly on his sweeper and his four-seam. This has been a talking point for Wesneski since early in the season, and while early on, the goal was to have him release his four-seam and cutter from similar windows, now it seems like he wants his sweeper to come from a similar release point as well.
If we check his Statcast data from Friday, we can see that every pitch was up almost two miles per hour, and there was a noticeably increase in spin rate on his sweeper. Lance Brozdowski even put numbers to it by saying that Wesneski had gained 2-3" in extension which had improved his pitch grades slightly on both FanGraphs and Driveline’s Stuff+ models. In that start on Friday, he had a 47% whiff rate and 46% CSW.
Granted, it was only 35 pitches in two innings, but he struck out four batters and I think these changes are all positive developments for the young pitcher. If the Cubs intended to stretch Wesneski back out until he can complete five-plus innings, he’s an arm I’m keeping on my radar in fantasy leagues.
Michael Grove - Los Angeles Dodgers
Lastly, we’ll end with a pitcher who may not be in his own rotation for much longer. With Lance Lynn in town, and the Dodgers reportedly interested in acquiring Justin Verlander or other starters, both Michael Grove and Emmet Sheehan might be back in Triple-A in the coming weeks. However, until that time, I want to highlight something Grove has been doing.
On June 23rd, Grove added a cutter and started to dial back on his slider usage. Then, on July 24th, he kept his cutter but spiked his slider usage. The next start, he kept the slider usage high, but dialed back the cutter more and increased his curve usage. While he’s yet to settle in on a specific pitch mix, it’s clear that Grove is tinkering with his arsenal in the hopes of settling on one that can give him the success at the major league level that he saw in the minors.
However, while Grove’s performance has been a bit of a mess through all these changes, a couple of things stand out to me.
For starters, the cutter is a decent pitch. It’s 89.1 mph with just 4.5 inches of horizontal movement and 27.3 inches of vertical drop. It’s allowed a .273 average but has yet to allow a barrel and has a 19.6% SwStr% which has led to a 0.87 ERA. It also makes for a strong pairing with his slider, which is Grove has started throwing slower, getting it down to 85 mph last start, while adding slightly more break and bite.
With the two pitches featuring prominently in his arsenal, Grove struck out 16 hitters in 10.2 innings. He posted a 38% whiff rate and 33% CSW on Sunday and a 38% whiff rate and 32% CSW last Monday. However, he also gave up 18 hits and 10 earned runs in those two games against the Blue Jays and Reds.
What I see from all of this is a young pitcher who has identified two pitches that seem to work for him in the slider and cutter. He also has a curve that has performed well in limited usage this year. This is an arsenal that has flashed a 13.6% SwStr% in the month of July. However, since he only uses the cutter against lefties, Grove is still forced to throw a four-seamer that has given up a 10.7% barrel rate this month and posted a 9.69 dERA.
There are some intriguing pieces here that didn’t exist in April or June, and I think Grove is just one tweak away from becoming an intriguing fantasy starter. Can he use his cutter to righties? Can he add a two-seam instead of the traditional four-seam? Can he lean heavily into the slider and curve to hide his fastball? I’m not sure what the answer is yet, but I’m curious to see how the Dodgers solve for it, even if they wind up doing it in Triple-A.
Of course, there’s also the chance that the Dodgers trade him as part of their package for an established veteran starter. If that’s the case, we have to hope he winds up in an analytically-inclined environment that can help him continue this exploration.
