A Dozen Arms of Hope

how optimizing data could save some pitchers careers

While doing my model on free agents, I found a few guys coming off down years. In my natural curiosity, I thought of possible ways how these players could improve. In this article I will state why their current pitch mix isn’t working and how each pitcher can improve their pitch mix to optimize results for next year.

I want to thank Remi Bunikiewicz for the inspiration for this list. I’ve looked on twitter and have seen him make one detailed thread after another on how to fix pitchers through looking at velocity, spin rates, delivery characteristics, and tunneling of stuff. If his thread is 10% as good as his content is, I will be satisfied.

To be qualified for the list, you must have a 4 ERA or higher this year and at least 1 season in the past with an ERA under 4. You also have to be a free agent this upcoming offseason(or on the free market now without team control). There’s no minimum inning rule this year. Pitchers will be listed in alphabetical order of their last name. Pitch types will be abbreviated by the way they appear on Baseball Savant.

Scott Alexander(RP)

Current team: None(Free agent)

Age(next year): 36

2025 ERA: 6.11

Current pitch mix: SI(65%)/SL(21%)/CH(14%)

Why it isn’t working: Scott Alexander’s strikeout rate is at 9.9% this year and a huge part of that is sinker overuse. He’s allowed a .340 AVG on that pitch this year with a 91.5 MPH average EV while having a putrid 12% whiff rate. On top of that, he’s struggled with righties, as sinkers are a relatively easy pitch for OHB to hit.

My changed pitch mix: SI(40%)/SL(30%)/CH(20%)/FF(10%)

Reason why: Believe it or not, Scott Alexander gets good whiffs on his slider(28%) and changeup(43%). Increasing the usage of both of those pitches will allowed for a well-rounded out profile for him. Adding a good four-seam fastball will be tough as he’s a natural supinator with a high VAA release point and low spin rate. However, occasional usage would allow him to attack the top of the zone, have another weapon against RHH, and increase whiffs.

Tyler Anderson(SP)

Current team: Angels

Age(next year): 36

2025 ERA: 4.77

Current pitch mix: FF(39%)/CH(33%)/FC(21%)/SI(4%)/SL(3%)

Why it isn’t working: Having only 3 pitches when your average fastball is 89.3 MPH is like playing with fire. He’s allowed 12 homers and a 91.6 MPH EV on the pitch while throwing it 39% of the time. I get that it’s necessary for his changeup to work, but he will need to expand his repertoire to deal with the velocity decline. On top of that, he needs to improve his paltry 30% groundball rate this year.

My changed pitch mix: CH(30%)/FF(20%)/FC(20%)/SI(12.5%)/SL(12.5%)/CU(5%)

Reason why: Time to go crazy. The first change is to cut his fastball usage in half. This will help with the home run issues(1.92 HR/9 this year), especially against righties. I'm going to triple the sinker usage, where he will throw the pitch to both hands in an effort to improve the groundball profile. I will also increase the slider usage to get him more strikeouts against lefties, which is something he sorely needs as a changeup heavy guy. Finally, I want him to bring back that slow curve. It can be used for called strikes against both hands and keep the hitters off edge. Anderson is a crafty pitcher and expanding his arsenal should help him defeat Father Time.

Ryan Borucki(RP)

Current team: Pirates(in DFA limbo)

Age(next year): 32

2025 ERA: 5.28

Current pitch mix: SL(41%)/SI(26%)/FS(17%)/ST(16%)

Why it isn’t working: Ryan Borucki is one of my favorite under the radar pitchers in the league. He has great results on his slider, sweeper, and split finger. However, his sinker is causing him problems. First off, it has an extremely low whiff rate(6.9%). However, the worse part are the splits he’s running with the pitch. Righties have hit the sinker 10.4 MPH harder than lefties against him this year. With the three batter rule, it will be tough for him to currently get any leverage opportunities.

My changed pitch mix: SL(45%)/FF(15%)/FS(15%)/ST(15%)/SI(10%)

Reason why: Ryan Borucki needs three things to improve as a pitcher: improve versus righties, have a higher K/9, and stop getting hurt. I can change the first two through adding a four-seam fastball. He seems like a natural supinator with a high VAA, so I’m expecting dead-zone shape. However, his low arm angle could make this pitch effective up in the zone. I’m willing to take the risk with his batted ball profile to make sure that he can get batters of both hands out. I just hope that he can stay healthy, as he has legit potential as a mid/high leverage guy.

He got recently DFA’d, so I’m interested to see who takes a chance on him this year. Hopefully, it’s an analytically friendly organization that will help optimize his stuff.

Walker Buehler(SP)

Current team: Red Sox

Age(next year): 31

2025 ERA: 5.43

Current pitch mix: FF(24%)/FC(18%)/SI(16%)/SL(15%)/CU(13%)/ST(7%)/CH(7%)

Why it isn’t working: Walker Bueller’s formerly elite fastball has become terrible, as batters are hitting .329 with a 93.0 average EV against it this year. The pitch has massively declined in velocity(94.1 MPH), IVB(16.2 in), and Stuff+(97). To compensate for that, he’s added a 6 other pitches to help hitters with varying degrees of success. Regardless, his ceiling as a starter is very low if he continues in that role.

My changed pitch mix: CU(20%)/FC(20%)/SI(15%)/FF(15%)/SL(10%)/ST(10%)/FS(10%)

Reason why: Walker Buehler is yet another guy I want to see convert to a full-time reliever. He has the stuff, personality, and clutchness(got the last out of the 2024 World Series) to excel in this role.

To righties, I want to see Buehler pare down his four seamer usage and become a sinker-first pitcher for about a third of his pitches. Next up, I want him to be heavy on his breaking ball usage. He needs to massively increase his curveball usage, as he’s gotten a 46.7% whiff rates versus righties on that pitch. I would also keep solid use of the sweeper and slider, as both have solid whiffs/contact profiles against opposite handed batters. Finally, an occasional cutter and four seam fastball is good for called strikes around 10-15% of the time. .

To lefties, I want to see Buehler do the opposite he does to righties. I want him to cut out his sinker usage and throw four seamers as his primary fastball(around 30% of the time). I would keep the cutter and curveball, as both are useful for getting called strikes and soft contact. Finally, I want to add a whiff pitch to lefties for him. As a supinator, a splitter would help him get better spin killing, vertical drop, and velocity separation than his current changeup.

I think that his velocity and stuff will benefit massively through a change to relief. I would personally have him in a multi-inning leverage role, which is something I find underrated and valuable in today’s league.

Jack Flaherty(SP)

Current team: Tigers

Age(next year): 30

2025 ERA: 4.76

Current pitch mix: FF(47%)/KC(26%)/SL(23%)/CH(3%)/SI(2%)

Why it isn’t working: Jack Flaherty throws his four-seam fastball way too much. He’s given up 13 HR and a 92.3 average EV on the pitch thanks to low IVB(15.1) and Stuff+(100) . It has led to a mediocre overall batted ball profile with poor groundball(34%), EV(89.9), barrel(12%), and hard-hit(43.9%), and home run(1.5/9) rates. He’s also run into struggles versus lefties this year, having a 5.92 ERA versus them compared to a 3.61 ERA versus righties.

My changed pitch mix: FF(30%)/KC(30%)/SL(15%)/SI(15%)/CH(10%)

Reason why: The first and most important part of improving Flaherty is to cut the fastball usage by a significant amount to help improve the batted ball profile. It’s still a fine pitch to help the knuckle curve, but doesn’t need to be thrown half the time. Next up comes massively increasing the sinker usage. This is definitely a risk thanks to the sinker’s mediocre shape(81 Stuff+), but he desperately needs to improve his batted ball profile. Finally, I want to see him up the changeup usage. It’s been good for whiffs/hard contact suppression against lefties in a small sample size. I’m very intrigued to see how it does in a larger one.

It’s important to remind people that Flaherty has a player option for next year. I’m honestly 50/50 if he opts out, as it’s good that he’s pitched another full season but he’s coming off a down year.

German Marquez(SP)

Current team: Rockies

Age(next year): 31

2025 ERA: 5.67

Current pitch mix: FF(34%)/KC(31%)/SI(24%)/SL(11%)/CH(2%)

Why it isn’t working: German Marquez is yet another example of fastball overuse, as his four seamer and sinker are combining for 55.3% usage. Both got crushed, as his four seamer has allowed a .336 AVG, 6 HR, and a 92.1 avg EV this year while his sinker has allowed a .364 average against, a 91.4 EV, and an EMBARRASSING 4.8% whiff rate against. Both of these pitchers have well below average stuff FF(65 Stuff+), Sinker(75 Stuff+), which is another huge red flag. His changeup is poor as well, with only 6 MP It’s also important to remind people how his ERA was bad both in and out of Coors. Finally, he’s averaged less than 5 innings per start this year, which shows concern for future durabiliy long-term.

My changed pitch mix: CU(40%)/FC(30%)/FF(30%)

Reason why: Screw it, I’m making German Marquez a reliever. With him struggling to make it deep in games and having two poor fastballs, I don’t see much of a future as a starter for him.

The good news is that Marquez has high leverage potential as a reliever. This is due to his curveball. With an 85.1 MPH avg velocity, 38% whiff rate, and a 112 Stuff+ it is a standout pitch. He’ll need to zone it better(34% zone rate) for it to work as a true primary. As a bridge pitch, I want to Marquez to replace his slider with a harder cutter. That would allow him to get called strikes and some grounders. I also see his fastball improving outside of Coors, where he should get around 2 inches of IVB back. I’m expecting better results, especially with an uptick in velocity as he pitches less innings.

Colin Poche(RP)

Age(next year): 32

Current pitch mix: FB(72%)/SL(28%)

2025 ERA: 12.54

Why it isn’t working: When your ERA is 12.54 and your BB/9 is 27.50, it’s obvious that things need to change. The first thing I need to look at is his fastball. Despite good IVB(18.3), his overhand delivery and below average velocity(92.2 MPH this year) has rendered this pitch as below average by Stuff+(95). There is no way he should be throwing that pitch 72% of the time. On top of that, Poche slider and fastball don’t have the best tunnel. Right handers have made quality contact against it(91.2 MPH EV in 2024), which is a huge issue in the 3 batter rule era.

My changed pitch mix: FB(40%)/KC(40%)/SI(15%)/SL(5%)

Reason why: There are a few big changes I want to see with Colin Poche if he wants to have any success. The first is to massively cut his fastball usage. I still really like the pitch shape, but the spam is hurting the pitch’s result. The second is to give him a platoon neutral breaking ball to get strikeouts. Insert a death ball curveball. He has the vertical arm angle to do it, and it should work perfectly off his high IVB fastball. With his high VAA, adding a sinker makes sense. It will allow him to get more grounders and use the bottom of the zone more effectively. I thought about ditching the slider entirely, but it’s fine as a secondary breaker to lefties.

Jordan Romano(RP)

Age(next year): 33

2025 ERA: 7.18

Current pitch mix: SL(63%)/FF(37%)

Why it isn’t working: Jordan Romano has 2 issues: 1. his fastball is getting crushed(.326 AVG, 53HR) and 2. his fastball/slider combo are way too easy to discern out of his hand. It is important to remind that Romano’s fastball is at a career-low velocity(95.5 MPH) and stuff(102 Stuff+), which is a huge reason why he’s declined so much this year.

My changed pitch mix: SL(45%)/FC(20%)/FF(20%)/SI(15%)

Reason why: Jordan Romano doesn’t have the stuff right now to be effective as a two pitch pitcher. Adding a cutter will help with the issue of his fastball/slider being too predictable to come out of his hand and also improve his batted ball profile. I also want to see him add a sinker to add yet another fastball shape against RHH and improve his contact profile. His sinker shapes haven’t been the best in the past, but all it needs to do is be a serviceable fourth pitch for him.

Joe Ross(RP)

Current team: Phillies

2025 ERA: 4.78

Current pitch mix: FF(38%)/SI(27%)/SL(23%)/CH(8%)/CU(5%)

Why it isn’t working: Joe Ross doesn’t have good enough fastball shapes to be throwing them 65% of the time. His fastball has an 87 Stuff+ this year and his sinker isn’t much better with 96 Stuff+. His sinker has a 12.3% whiff rate On top of that, he has an atrocious changeup that doesn’t have enough separation(4.6 MPH) from his fastball, which causes him to struggle against lefties. Finally, he gets very little separation between all of his pitches. His fastball has only 10.1 IVB while his curveball has a mere 44.1 inches of vertical drop, which are both well below average movement profiles.

My changed pitch mix: SL(35%)/FF(25%)/CU(15%)/SI(15%)/FS(10%)

Reason why: The first thing I would do with Joe Ross is to work and see if you can do anything to improve the shapes of his pitches. Perhaps sending him to Driveline for a week or so would help with this issue. There could also be delivery issues that I’m not seeing.

The first thing I’m looking at here is cutting down the fastball usage. He had success last year with a slider primary, and I want him to return back to that. His slider can get called strikes, whiffs, and soft contact. Next up, I want him to increase his curveball usage. At 83.5 MPH and 116 Stuff+, this pitch has high level potential. The results weren’t there last year(.294 AVG, 90.4 MPG EV, 16.7% Whiff%), but I think that throwing the pitch more can lead to better comfort. I want to make are lowering the usage of his sinker due to a paltry 12.3% whiff rate this year. Finally, I’d like to see him add a splitter versus lefties as his natural supinator tendencies could allow him to get more drop(and better results) on that pitch than his changeup.

Lucas Sims(RP)

Current team: Phillies(minors)

Age(next year): 32

2025 ERA: 13.86

Current pitch mix: FF(44%)/ST(44%)/CU(4%)/SI(4%)/FC(3%)/SL(2%)

Why it isn’t working: Lucas Sims is a talented pitcher but he has many problems. First off, he struggles to get any lefties out. Second off, it’s way too easy to discern his fastball from his sweeper out of his hand. Third of all, his zone rates are terrible, leading to lots of walks. Finally, his batted ball profile is iffy, as he gets very few ground ball outs.

My changed pitch mix: FF(30%)/ST(25%)/FC(15%)/FS(10%)/SI(10%)/CU(10%)

Reason why: To help with the tunneling problem between his fastball and sweeper, I want Lucas Sims bring back his cutter usage from 2024. To help with lefties, I want Lucas Sims to add a splitter. I don’t know his ability to kill spin, but it’s worth trying. Next up, I want to slightly increase Sims’ sinker usage. It isn’t a great pitch or anything, but could help with ground balls, especially if he can change the grip from this year. Finally, I’m going to double the curveball usage so that he can get more called strikes early in the count and have another weapon that’s usable against lefties.

Mike Soroka(SP)

Current team: Cubs

Age(next year): 28

2025 ERA: 4.86

Current pitch mix: FF(45%)/SV(35%)/SI(10%)/CH(10%)

Why it isn’t working: Soroka has done a great job adding a slurve this year that has a .126 average and 38% whiff rate. I can’t say the same about his fastball, which has allowed 9 HR and 91.9 EV. With below average IVB(14.6 in) and 90 Stuff+, this pitch doesn’t have the characteristics to be used so much.

My changed pitch mix: FF(30%)/SV(30%)/FC(20%)/CH(15%)/SI(5%)

Reason why: Mike Soroka has a big velocity(13.2 MPH) and movement difference between his fastball and slurve. Getting a cutter would help bridge those pitches, help with soft contact, and help him cut down the usage of his low-movement fastball. I also want to see him increase changeup usage to help with his issues with lefties. Otherwise, I really like his arsenal and expect a big year for him next year.

Ryne Stanek(RP)

Current team: Mets

Age(next year): 34

2025 ERA: 5.05

Current pitch mix: FF(59%)/SL(20%)/FS(12%)/ST(8%)

Why it isn’t working: I can honestly say that part of it is bad luck on the splitter, which has a .375 AVG(which is 129 points higher than his expected AVG) on the pitch. But, he’s still throwing too many fastballs. He has good stuff(106 stuff+) and IVB(18.1 inches) on the fastball, but the average fastball is much easier to hit than the average slider. That is especially true considering that his has a 128 Stuff+ and 45.7% whiff rate this year.

My changed pitch mix: SL(40%)/FF(25%)/FS(15%)/SI(10%)/ST(10%)

Reason why: I want Ryne Stanek to pitch backwards. His slider is nasty and should be his primary pitch. Based off my short film watch, I trust the command enough for this to work. This should help with unpredictability and also improve the fastball’s effectiveness. I also want him to add a sinker, as his four seamer isn’t great in the bottom of the zone and he struggles to get grounders versus righties.

We must also talk about his mechanics. It feels like he’s prone to overthrowing and having inconsistent strides. I’m no expert, but having more consistent mechanics should help with his command and lower his walk rate.

Devin Williams(RP)

Current team: Yankees

Age(next year): 31

2025 ERA: 5.32

Current pitch mix: CH(53%)/FF(47%)

Why it isn’t working: The first thing that you can see when looking at Williams’ stats is that his strikeout percentage(31.8%) is his lowest since 2019. This is especially true against lefties, where his strikeout rate is a mere 22.6%. against them Another huge red flag is a declining changeup whiff rate(35%), especially against lefties(24%). He also struggles with zone rates(47% overall, 37% on changeup) and is prone to giving up more hard contact than normal this year(89.6 MPH avg EV, 9.8% barrel rate)

My changed pitch mix: CH(40%)/FF(35%)/CU(15%)/FC(10%)

Reason why: When I’m looking at how to improve Devin Williams’ arsenal, I find two issues. 1. have more pitches that he can throw in zone to both handed batters. 2. get a pitch that gets whiffs versus left handed batters. I found the solution to option 1 to be relatively easy. A cutter(which he has thrown in the past) would help him get strikes and get him a pitch that doesn’t move arm side. The harder part is getting a strikeout pitch versus lefties, considering that his changeup(a typical reverse split pitch) is doing better versus righties. The best idea would be some sort of death ball curveball that he has enough feel for in the zone. However, with a low arm angle, I’m not sure how that will work. Regardless, I think that a curveball could tunnel well with his changeup and cutter, allowing for both called strikes and whiffs. I just hope that Williams can get out of NY, as he’s a good pitcher.

While doing this article, there were a few key things that I noticed on why pitchers need arsenal changes:

1. Decline in stuff

As pitchers throw more innings and get older, their stuff tends to decline. The best way to counter this is to introduce more pitch shapes to keep hitters off balance. It is also important to look at ways to improve pitch shapes and mechanics if needed. Finally, a change in role(particularly looking at starter to reliever) might be necessary.

2. Fastball usage is too high

Even if the year is 2025, and fastball usage is approaching new lows, there are still pitchers who throw too many fastballs. One of the first things I will look for in making changes is seeing if someone is throwing a fastball with poor results/stuff too often. Fastballs can still be important, but fans must realize that strong breaking balls will always be better strikeout pitches than strong fastballs.

3. Lack of a bridge pitch

Some pitchers have great stuff, but struggle because of the fact that batters can see the difference between their fastball and offspeed, allowing them to lay off of breakers. Getting a bridge pitch solves that issue and allows for more called strikes and soft contact.

4. Lack of a whiff/out pitch to both handed batters

With there being no 3 handed batter rule, both starters and relievers need to have the ability to get batters of both handedness out. Ideally, I would like them to have some sort of strikeout pitch for both hands. It is important to look at

5. Lack of a soft contact/groundball inducing pitch

Being a strikeout or bust guy is a very risky profile. These types of pitchers can get shelled by hard contact, leading to inconsistent year after year results. This is why I find it important for most pitchers to throw at least two kinds of fastballs: one for whiffs, and one for avoiding barrels. A downward-moving breaking ball could work as well, depending on the pitcher.

6. Underutilized pitches

Finally, there are times where a pitcher is throwing a pitch with great results but just not often enough. When that is the case, pitching staffs should evaluate why that is the case and make necessary changes with the entire arsenal. It is important to realize the role of said pitch in the entire arsenal, as some pitches are better with specific roles/handedness.

7. Delivery/command issues

I can’t say that I’m well versed in these. However, this is one thing teams should look at when a pitcher is struggling. A few signs to see are release point of all pitches, delivery consistency, and deception. To best understand these issues, I highly recommend watching film of the pitcher you will evaluate, as statistics can’t tell you everything on why a pitcher is good or bad.

8. Left-handed sinkerballers

Being a left-handed sinker-primary pitcher is very difficult in 2025. This is because sinkers do best against same-handed batters, and lefties face opposite-handed batters most of the time. I believe that the best way to solve this issue is through the use of an occasional four-seam fastball, cutter, or platoon-neutral breaking ball. Command is also extra important, as pitchers can get away with more if they know where their pitches are going.

9. Relief conversion

There comes a time where a starting pitcher would benefit as a move to reliever. This is generally the case for pitchers who have a poor fastball and plus breakers with good whiff rates. This allows pitchers to lower fastball usage, increase breaker usage, and have an overall increase in velocity/stuff. Of course, both sides have to agree before doing something like this.

Like always, want to thank everyone for making it to the end. I highly recommend anyone interested in analysis to do lots of research. Watch plenty of film. Look at team trends. Be okay with being wrong. Most importantly, have fun with it. Sports aren’t that serious. I hope that everyone has a great rest of their day.