Even though many pitchers will test new pitches in the spring, they can often be abandoned when the regular season starts. It can often be more informative to see which pitchers have drastically changed their pitch mix or pitch shape after a few starts in the regular season. It’s not as common, and the changes aren’t as drastic, but it allows us to see how a pitcher is reacting to what he’s seeing from hitters and gives us a glimpse into what the pitcher thinks he needs to do to be successful.
With that in mind, we will continue with the premise of the series I had called Pitchers with New Pitches (and Should We Care) by breaking down notable changes in a pitcher’s pitch mix (hence “Mixing” it up). We’ll look at pitchers throwing a new pitch, who have eliminated a pitch, changed their pitch mix meaningfully, or are showcasing a different shape/velocity on a pitch. It will mostly be positive changes, but sometimes we’ll point to a change we’re not excited about but could have a meaningful impact on a pitcher’s fantasy outlook.
I’ll continue my analysis with the simple premise that not every new pitch should be greeted with praise. A new pitch, like a shiny new toy, might be exciting on its own, but it also needs to complement what a pitcher already has and fill a meaningful void in his current pitch mix. We want to check and see if he has any splits issues. We want to see what his best pitch(es) is and see if this new pitch would complement that. Then we want to see what this new pitch type is generally used for (control, called strikes, etc.) and see if that is something this pitcher needs help with. We can also now see the pitch in action to look at the shape and command and see if it’s actually any good. Once we’ve done all that, we can decide if the pitch is a good addition or not.
If you missed any of the previous editions of this series, you can click this link here to be taken to the tracker, which I’ll update as the season goes on. It also includes links to the original articles so you can read them in full if you’d like.
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Bowden Francis - Toronto Blue Jays (Splitter, Curve)
In August, Francis moved back into the rotation but with a deeper arsenal of pitches. As you can see from Alex Chamberlain’s Pitch Leaderboard below, when Francis moved into the rotation on July 29th, he started to make a shift where he significantly dialed back his curveball usage while leaning heavily on the splitter and adding the slider in more. He also introduced a sinker, which he is throwing exclusively to righties.
These changes have led to a four-game stretch in which he’s posted a 2.16 ERA, 0.64 WHIP, and 24 strikeouts in 25 innings, so why might it be working?
Well, for starters, the curveball is just an average pitch for him. It grades up well in Pitcher List’s PLV metric because he has solid command of it, and Stuff+ says it’s slightly above average based on raw movement, but it has just an 8.6% swinging strike rate (SwStr%) on the season while allowing a 40% Ideal Contact Rate (ICR), which is slightly above average. So it doesn’t get hit overly hard but it also doesn’t miss bats, which is not a great pairing with a four-seam fastball that also doesn’t get hit hard but has just an average SwStr% itself.
In his last four starts, Francis has been going to the curveball to get called strikes but throwing the slider over 24% of the time to righties as his main secondary pitch and the splitter 36% of the time to lefties as his main secondary to them. While PLV and Stuff+ both prefer Francis’ splitter to his curveball, they are less enthusiastic about his slider. However, the results have been good.
On the season, the slider has a 64% strike rate with a 19% SwStr% to righties. It does give up a 50% ICR but that could be because Francis is keeping it low in the zone just 51% of the time and has thrown it middle-middle nearly 10% of the time. The command of the pitch wasn’t great for much of the year and despite it having a 36% putaway rate to righties, he was only throwing it in a two-strike count 19% of the time. That simply doesn’t make sense.
Over this hot stretch, Francis has buried the slider low in the zone 64% of the time to righties and thrown it middle-middle just 2.6% of the time. Those are huge improvements in command, which have led to a 40% ICR. Yet, despite the pitch getting a 33% putaway rate of this stretch, he’s using it in two-strike counts just 15.4% of the time and preferring to throw it early. However, in his defense, he’s using both the splitter and curve more to righties in two-strike counts and both of them have 33.3% putaway rates or higher, so that’s working for him at least.
While he will mix the splitter in against righties with two strikes, he attacks lefties with it both early in the count and late in the count. His season-long usage is just 26.3% to lefties, so that 36% mark during this hot stretch is a big uptick. The pitch doesn’t really miss bats, which is interesting for a splitter, posting just a 6.3% SwStr% against lefties in this last stretch; however, it has an above-average 63% strike rate and a 70% true first strike rate, so Francis is adept at using it early in the count, and, as we mentioned above, it’s been effective in two-strike counts against righties.
Since his four-seam fastball doesn’t miss many bats to lefties, he has just a 7.3% SwStr% to lefties over this stretch as opposed to a 16.8% mark to righties. Yet, as we’ve seen with Tanner Houck this season, as long as Francis is not getting hit hard by lefties, then if he can truly eat up righties with his new pitch mix, he can make it work.
Which leads to the last final tweak: the introduction of the sinker. On the season, Francis is giving up a 45.3% ICR on his four-seam fastball to righties and had a 10.2% mistake rate, so his command of the pitch left a little to be desired and righties were hitting it hard. The addition of the sinker gives right-handed batters another fastball variation to worry about, and since he keeps the sinker inside to righties 54% of the time, it has also kept them off the plate. That has led to an improved 35.7% ICR on the four-seam fastball to righties over the last four starts in addition to just a 33% ICR against the sinker.
I still wish Francis, who has a 17.2 iVB on his four-seam fastball, would throw it up in the zone more. He’s using it up in the zone just 48% of the time to righties, and I think if he elevated it a bit more, he could miss even more bats, which would be great for his value.
VERDICT: MEANINGFULLY IMPACTFUL. I don’t know if we’re seeing a full-on breakout, but Francis was no longer on fantasy radars until this pitch mix change, so the fact that you can even stream him means the changes have made a meaningful impact. He has deepened his arsenal overall and traded out an average pitch for two pitches that are performing better. Reducing hard contact has raised his floor considerably, and I still think there is some room for even more improvement if he can change the attack plan on his four-seam fastball.
Michael Lorenzen - Kansas City Royals (Fastball usage, Sweeper)
Last week we talked about how pitchers often make pitch mix changes after the deadline and mentioned both Zach Eflin and Trevor Rogers on the Orioles. Now we can see the same thing happening to Lorenzen with the Royals, specifically in the way the team has shifted his fastball usage and had him lean on his sweeper instead of his harder slider.
Lorenzen has seven different pitches and, on the season, doesn’t throw a single one more than 28% of the time, so his arsenal has always been about mixing and matching based on the handedness of the hitter. As a result, when we look at the changes that Lorenzen made, we really need to split it up based on whether he was facing righties or lefties.
When he was on the Rangers to start the season, Lorenzen threw his sinker as the main offering to righties at 32.5% of the time and also threw his four-seam fastball 23.7% of the time. That left his slider as his primary non-fastball, which he threw 14.3% of the time. He also threw a sweeper 10.7% of the time to righties and a change-up 9.6%. In three starts with the Royals, his combined four-seam and sinker usage against righties has dipped from 56.2% to 51%, and, perhaps more drastically, he has all but eliminated his harder slider and is now throwing his sweeper 24% of the time to right-handed hitters.
Cutting back on his fastball usage isn’t a bad thing since neither the four-seam nor the sinker miss many bats, and the sinker was giving up a 47.4% ICR against righties on the year. That’s not a good mark for a pitch that is meant to reduce hard contact. Now, the sweeper also hasn’t missed many bats on the year, but it gives up less hard contact than the slider, so that could be a net positive addition.
Similarly, Lorenzen is throwing his changeup to right-handers more now, which is nice since its season-long numbers to righties are good with a 17.8% SwStr% and a 16.7% ICR. That’s probably a pitch you want to use more often and the addition of the sweeper and changeup has helped his hard contact rate allowed.
Over his stretch with the Rangers, Lorenzen had an 8.1% SwStr% to righties with a 26.7% CSW and 40.4% ICR. In three starts with the Royals, he has just a 7.7% SwStr% and 26.5% CSW but his ICR has fallen to just 30.8%. That could certainly be attributed to facing the Tigers, Cardinals, and Reds, but he did pitch in Great American Ballpark, and the two pitches he increased the usage of are ones that have limited hard contact for him, so the results make a little bit of sense. We obviously don’t love his strikeout rate falling, but you were never turning to Lorenzen for strikeouts, so if he can limit the hard contact, that can still be a boon for his fantasy value.
He has also started to use his changeup and sweeper more in two-strike counts than his four-seam and sinker and while that hasn’t led to a massive strikeout boon, it’s a change that makes sense to me.
Against lefties, Lorenzen with the Rangers led with his four-seam 31.3% of the time but also leaned on a changeup 29% of the time and his cutter 18.3%. With the Royals, he has dropped his four-seam and cutter usage a combined 11% while adding in his changeup more and throwing his curveball now 17% of the time. Those changes have helped him push his swinging strike rate from 13% to 18% against lefties, and that’s not nothing.
The curveball itself isn’t an elite pitch, but it has posted a solid 13.8% SwStr% on the season against lefties, so it will help him miss some bats in a way that the four-seam fastball is not. I did think the cutter was a good pitch for him against lefties though. It grades out well in Pitcher List’s PLV metric, and he had a 13.6% SwStr% to lefties with a 36.6% ICR, so it missed some bats and didn’t get hit hard. I would try to bring that offering back a bit at the expense of the four-seam fastball.
VERDICT: MINIMALLY IMPACTFUL. Lorenzen is limiting the usage of fastballs that are only mediocre and also relying on them less with two strikes. That’s nice. It doesn’t make him a drastically different pitcher, but they’re nice changes for him if we want him to maintain his value as a solid ratio starter for deeper formats and a safe streamer in shallower leagues.
JP Sears - Oakland Athletics (Four-seam, change and sweeper)
Over his last four starts, from July 30th on, Sears has been lights out with a 1.57 ERA, 0.73 WHIP, and 27 strikeouts to just five walks in 28.2 innings. As you can see from the Statcast image below, we can also connect this surge in performance to a clear shift in pitch mix.
Sears has drastically cut back on his sweeper usage while increasing his changeup and four-seam usage and also modifying HOW he attacks with the four-seam. There are a lot of changes here, but let’s dig into all of them.
We’ll start with the fastball since JP Sears was featured in my pre-season article on pitchers with surprisingly good fastballs. In that article, I said, “In 2023, Sears’ four-seam averaged 93.1 mph with 6.6 feet of extension, and 13.8 inches of iVB. While that’s not great “vert,” Sears is a lefty, so he has an elite 11.6 inches of arm-side break on his fastball.” However, he also had “a 52% hiLoc% (high location) to righties that’s above average. As a result, the pitch has a .228 batting average against righties with a better SwStr% and ICR than when he tosses it to lefties.”
When the season started, Sears was doing a fine job getting his fastball up in the zone with a 56% hiLoc% overall and a 58% mark to righties, but it wasn’t a drastic change from what we had seen from him previously. Yet, over his last four starts, that has jumped up to a 64.2% hiLoc% overall, which includes a 76.2% mark to lefties and 63% mark to righties. That has led to a stellar 22.3% SwStr% on his four-seam, up from 12.4% before this recent stretch. He’s also allowing just a 29.6% ICR overall and a 40% mark to lefties, which is an improvement from his previous marks of a 41% ICR overall and 46.2% to lefties.
The confidence in his four-seamer has borne out in his desire to challenge hitters with it early. He’s now using the fastball early in the count 55.4% of the time, up from 41% in the earlier part of the season, and when he does go to it with two strikes, the elevated location on that pitch has improved his put away rate from 23% to 31.3%. There is just no marker where the four-seam fastball has not been significantly better over the last month.
We also love to see that Sears has been dialing back the sweeper usage. On the season, the pitch has just a 10.6% SwStr% and a 39% ICR but those numbers fall to an 8.6% SwStr% and 41.3% ICR against righties, which are obviously the hitters he faces most often. It’s not a bad pitch overall, and his 14.1% SwStr% and 35% ICR to lefties will work, but he didn’t need to throw it 22.8% of the time to righties, as he was doing before this hot stretch.
Since July 30th, he’s throwing the sweeper just 8% of the time to righties but has kept it 25% of the time to lefties. Considering the four-seam fastball is putting up such stellar SwStr% numbers, he doesn’t need another big swing-and-miss pitch to right-handed hitters, but he does need one that limits hard contact, which is exactly what the changeup has done.
In his last four starts, Sears has gone to the changeup 23.8% of the time, up from 17.7% before this stretch. He also uses the pitch primarily to righties and is attacking right-handed hitters with it 29% of the time. That means he’s been attacking righties with either the four-seam or changeup 78% of the time and then minx in his sweeper, sinker, and harder slide for the remaining 12%. While that’s a five-pitch mix, the success has been driven by using the four-seam up in the zone and the changeup on the outside part of the plate to righties.
Over the last four starts, the changeup has allowed just a 5.3% ICR to right-handed hitters on the changeup while producing a 62% strike rate and 17.4% called strike rate. He’s keeping the pitch away from righties 70% of the time but using it all over the zone from a vertical standpoint. As a result, he’s improved his strike rate and swinging strike rate while reducing his hard contact allowed over this last stretch. There are no complaints at all.
VERDICT: MEANINGFULLY IMPACTFUL. Sears has tweaked an already strong pitch to make it better simply based on location and usage. He’s then cut back on one of his weaker pitches to righties and added a pitch that not only gets more weak contact but is one he can throw in multiple areas of the strike zone. All of these are positive changes for the left-hander, and while I think he’s pitching over his head from a results perspective of late, we love the changes and I think this is true positive growth from Sears.