Article: Justin Slaten Comes Out of Left Field (Well, Actually Right Field)

[Davy Andrews]

The rookie right-hander's setup makes him very nearly unique among today's pitchers.

By any measure, Justin Slaten had an outstanding rookie season. The 27-year-old right-hander, scooped up from the Rangers organization in the Rule 5 Draft last December, threw 55 1/3 big-league innings over 44 appearances. He ran a 2.93 ERA, and as his 2.61 FIP indicates, the underlying numbers loved him as well. He limited hard contact, especially in the air, and got plenty of chases and whiffs. His 35% chase rate, 4% walk rate rate, and 4% barrel rate all put him in the 96th percentile or better. He was also just plain fun to watch.

I don’t just mean that it was fun to watch him carve up opposing lineups. I loved watching him because he pitched a little differently than everyone else on the Boston staff, and in fact, everyone else in baseball. Before you look at the picture below, scroll back up and take another look at the picture at the top of this article to see if you notice anything special about it.

Give up? Okay, I’ll help you out. Below is the same picture, but this time I’ve added Greg Weissert into it as well. Weissert’s screengrab is from the same game and camera angle, and also from the moment he releases the ball.

It's not just that Weissert is a side-armer and Slaten throws over the top. It’s that Weissert is all the way over to the third base side of the rubber, while Slaten is all the way over to the first base side. Slaten’s spot is particularly unusual for a right-handed pitcher, and when you combine it with his 6-foot-4 height and relatively steep arm angle, the result is a release point that’s even more unusual. In that picture, Slaten is releasing the ball almost exactly in the middle of the rubber and the plate. His release point is just 2.16 inches from dead center. Here’s how his average release point stacks up on the Red Sox. Slaten is the red dot.

There’s nobody particularly close to him. He’s the only player on the team whose release point is within one foot of the middle of the rubber. And just to be clear, this is almost entirely a result of his spot on the rubber. The graphic below comes courtesy of Statcast. Take a look at how Slaten’s arm angle stacks up compared to the rest of the team’s pitchers.

He has one of the steeper arm angles, but he doesn’t really stand out at all. It’s his positioning that makes him such an outlier, and not just on the team. Even if you zoom out to the entire league, Slaten’s release point is still extremely rare. Here’s the average release point of every single pitcher who faced at least 30 batters this season. Once again, Slaten is in red, and once again, he’s found his own niche.

Keep in mind, there are 699 pitchers on this chart. Very, very few of them have a release point similar to Slaten’s. Look how many of them overlap in the traditional righty or lefty blob, while Slaten is all the way off to the edge. His average horizontal release point is -0.82 feet, or just under 10 inches from the center of the pitching rubber. Among right-handed pitchers, that puts his horizontal release point in the 94th percentile, and because he achieves it with a higher-than-average release point, he still stands out, even when compared to every other pitcher in the league. This isn’t exactly a new phenomenon either. In July, Eric Longenhagen noted that Slaten had moved over on the rubber more this season, but here’s Slaten pitching for the University of New Mexico back in 2019. Even back then, he was pretty far over.

There’s a chance Slaten’s extreme release point may hurt his performance against right-handed hitters slightly. I’ve done a bit of research on horizontal release point, specifically looking at the small number of extremely fun pitchers who scooch from one side of the rubber to the other depending on the handedness of the batter. It’s a lot harder to hit a ball that starts out way behind you, which is one of the reasons that batters struggle against same-handed pitchers. The opposite is also true though: pitches that come from an extreme horizontal release point are hard for same-handed hitters, while pitches that come from close to the middle of the rubber are more platoon neutral. Slaten’s platoon splits were fairly even in 2024, and thanks to his reliance on his cutter, a pitch that often works well against same- and opposite-handed batters, we should probably expect more of the same going forward. That should be helpful in a bullpen that currently skews right-handed.

There’s one more benefit to Slaten’s setup. Generally speaking, pitchers want their pitches to look unusual to hitters. Major league batters boast excellent vision and hand-eye coordination, and some of their skill comes from elite pattern recognition. They’ve learned over thousands and thousands of reps what to expect from a pitch. Any time you can show them something surprising, you’re starting out a bit ahead of the game, and smart pitching analysts are working hard to quantify what they call – in open defiance of the English language – pitch uniqueness. Pitching from an unusual spot is helping Slaten throw something new at a hitter. Literally. 

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[moonslav59]

Great article.

[mvp 78]

Moves like Slaten are what give me hope for Breslow. He was decisive during the Rule 5 draft and traded to get him. There was clearly something in the metrics and scouting that they saw and it really worked out. 

[moonslav59]

12 minutes ago, mvp 78 said:

Moves like Slaten are what give me hope for Breslow. He was decisive during the Rule 5 draft and traded to get him. There was clearly something in the metrics and scouting that they saw and it really worked out. 

Agreed, and I am holding out hope that moves like I Campbell, Weissert and Sandlin will payoff, too.

Then, there is Fitts, Priester and Criswell, who are all pre-arb, until 2027.

[mvp 78]

51 minutes ago, moonslav59 said:

Agreed, and I am holding out hope that moves like I Campbell, Weissert and Sandlin will payoff, too.

Then, there is Fitts, Priester and Criswell, who are all pre-arb, until 2027.

Verdugo: 0.7 bWAR

Weissert: 0.6 bWAR

Seems like a fair deal...

Oh, the Sox also got Fitts 0.6 bWAR and a 6'8" developmental pitcher? That one paid off IMO.

[moonslav59]

1 hour ago, mvp 78 said:

Verdugo: 0.7 bWAR

Weissert: 0.6 bWAR

Seems like a fair deal...

Oh, the Sox also got Fitts 0.6 bWAR and a 6'8" developmental pitcher? That one paid off IMO.

The best part is that Dugo's end of the trade is over after 2024. Fitts, Weissert and Judice have years to go.

Other deals have a ways to go on 1 or both sides:

+0.2 Priester for -0.2 Yorke

-1.2 I Campbell for +0.4 Urias (end of control) Note: ICampbell was +0.5 in '23.

+2.7 O'Neill (end of control) for 0.0 Nick Robertson & n/a Santos 

I won't bring up the ATL trade players.

[5GoldGlovesOF,75]

1 hour ago, mvp 78 said:

Verdugo: 0.7 bWAR

Weissert: 0.6 bWAR

Seems like a fair deal...

Oh, the Sox also got Fitts 0.6 bWAR and a 6'8" developmental pitcher? That one paid off IMO.

In evaluating any trade, there is also qualitative data to consider.  I'm not a scientist, but in regards to overall clubhouse chemistry, the addition by subtraction of Verdugo may be represented by these elements:

C - (AR + T) = HeP 

Translated in guinea pig latin:

Carbon (element that forms the most compounds; in other words, team) minus Arsenic and Tungsten (poison tongue) brings Helium and Phosphorus (uplifting glow!).

[notin]

33 minutes ago, 5GoldGlovesOF,75 said:

In evaluating any trade, there is also qualitative data to consider.  I'm not a scientist, but in regards to overall clubhouse chemistry, the addition by subtraction of Verdugo may be represented by these elements:

C - (AR + T) = HeP 

Translated in guinea pig latin:

Carbon (element that forms the most compounds; in other words, team) minus Arsenic and Tungsten (poison tongue) brings Helium and Phosphorus (uplifting glow!).

You’re absolutely right.  You’re not a scientist.

You are correct that tungsten is poisonous and about the bonding abilities of carbon, however.  So some points awarded .

But Ar is argon, not aresenic.  Argon is a noble gas but more important the namesake of Jason’s ship, in which he and his teammates traveled to seek the Golden Fleece while fighting stop motion skeletons.  So maybe more relevant.

 

Tungsten is W.  So are wins.  A deduction is in order…

[5GoldGlovesOF,75]

28 minutes ago, notin said:

You’re absolutely right.  You’re not a scientist.

You are correct that tungsten is poisonous and about the bonding abilities of carbon, however.  So some points awarded .

But Ar is argon, not aresenic.  Argon is a noble gas but more important the namesake of Jason’s ship, in which he and his teammates traveled to seek the Golden Fleece while fighting stop motion skeletons.  So maybe more relevant.

 

Tungsten is W.  So are wins.  A deduction is in order…

I knew I could count on you to point out my typos, but can't believe you didn't catch my spelling on the arsenic tonguesten Verdugo compound resulting in poisonous tung.

[notin]

26 minutes ago, 5GoldGlovesOF,75 said:

I knew I could count on you to point out my typos, but can't believe you didn't catch my spelling on the arsenic tonguesten Verdugo compound resulting in poisonous tung.

Hey I liked using Argon over Arsenic.  Although Arsenic and Old Lace is a wonderful classic movie (and the best thing Cary Grant ever did by a long shot),  it does fall short of Jason and the Argonauts.

Your spelling of arsenic? You’re the one who spelled it right..

I didn’t correct your typos; I corrected your chemical symbols.  Not my fault you fast-forwarded the opening credits of Breaking Bad… 

[moonslav59]

You guys are killing it, today.

[5GoldGlovesOF,75]

52 minutes ago, notin said:

Hey I liked using Argon over Arsenic.  Although Arsenic and Old Lace is a wonderful classic movie (and the best thing Cary Grant ever did by a long shot),  it does fall short of Jason and the Argonauts.

Your spelling of arsenic? You’re the one who spelled it right..

I didn’t correct your typos; I corrected your chemical symbols.  Not my fault you fast-forwarded the opening credits of Breaking Bad… 

For any kid who almost grew up half a century ago, the following declaration is non-negotiable: the dragon teeth skeleton seeds in Jason and the Argonauts produced the most intense TV battle scene of the Sixties and Seventies, right up there with Wolfman vs. Dracula in the castle balcony with Frankenstein stumbling around Abbott and Costello. 

[Nick]

Five more years of team control on Justin Slaten. I hope he can continue his success. Always a crap shoot with relievers.

[Nick]

I'm wondering why we haven't moved others to middle of the rubber. 

Surely an analysis exists to extrapolate success/failure rate for each pitcher if they change their release point relative to the rubber.

 

 

[moonslav59]

2 hours ago, Nick said:

I'm wondering why we haven't moved others to middle of the rubber. 

Surely an analysis exists to extrapolate success/failure rate for each pitcher if they change their release point relative to the rubber.

 

 

I think a lot of teams keep their better pitchers as SP'ers for as long as it seems like they have a shot to be a good one.

[smokedogg1982]

18 hours ago, mvp 78 said:

Verdugo: 0.7 bWAR

Weissert: 0.6 bWAR

Seems like a fair deal...

Oh, the Sox also got Fitts 0.6 bWAR and a 6'8" developmental pitcher? That one paid off IMO.

Verdugo has helped the Stankees in the posseason. IMO the best part of that trade is Cora told everyone that Verdugo was lazy and had no work ethic. On Foul Territory Pap was talking about how he would show up 15 minutes before the game in a Dodge Hellcat with obnoxiously loud exhaust pipes. 

[moonslav59]

7 hours ago, smokedogg1982 said:

Verdugo has helped the Stankees in the posseason. IMO the best part of that trade is Cora told everyone that Verdugo was lazy and had no work ethic. On Foul Territory Pap was talking about how he would show up 15 minutes before the game in a Dodge Hellcat with obnoxiously loud exhaust pipes. 

I'm glad we traded Dugo, and the deal allowed Abreu and O'Neill to play.

WIN (no Dugo), WIN (more Abreu), WIN (more O'Neill), WIN (Weissert) and maybe win (Fitts & Judice)

[moonslav59]

fWAR

+0.6 Dugo

+0.5 Fitts, +0.5 Weissert

Opening made for more playing time for  +3.1 Abreu, +2.5 O'Neill and +1.2 Ref

[Larry Cook]

3 hours ago, moonslav59 said:

fWAR

 

+0.5 Fitts, +0.5 Weissert

 

In today’s game, depth is more important than ever. Our pitching staff was not nearly deep enough in 2024 and our pitchers ran out of gas in the second half. 
the fitts, weissert, Guerrero, and so many others should be depth pieces! 
it is bres-slow’s job to improve the bullpen so these guys are depth pieces 

[moonslav59]

2 hours ago, Larry Cook said:

In today’s game, depth is more important than ever. Our pitching staff was not nearly deep enough in 2024 and our pitchers ran out of gas in the second half. 
the fitts, weissert, Guerrero, and so many others should be depth pieces! 
it is bres-slow’s job to improve the bullpen so these guys are depth pieces 

Depth is very important, and our 2024 depth almost got us to the dance. (Houck, Craiswell & Fitts did a great job replacing Gio and Whitlock.)

IMO, if we add 1 top SP'er and 3 solid RP'er, our depth will become a strength. We already have 16-17 everyday players for 13 slots, on that side of the game.

[Larry Cook]

On 10/19/2024 at 9:19 PM, moonslav59 said:

Depth is very important, and our 2024 depth almost got us to the dance. (Houck, Craiswell & Fitts did a great job replacing Gio and Whitlock.)

IMO, if we add 1 top SP'er and 3 solid RP'er, our depth will become a strength. We already have 16-17 everyday players for 13 slots, on that side of the game.

And who replaced Chris not so frail????

[moonslav59]

8 hours ago, Larry Cook said:

And who replaced Chris not so frail????

The word was Houck replaced Gio. (He was likely the odd man out.) That would mean Criswell (the team went 12-6 in his 18 starts and Fitts (team went 0-4, despite his 1.74 ERA.)

The pitching depth of Houck, Criswell and Fitts were not the main issue: it was defense, the pen (including Martin's minor meltdown)  and the other 3-4 SP'ers (Bello, Crawford and Pivetta.)

My point is, we don't have great pen depth, as we sit now, unless we add 3 solid RP'ers, then our 6-7-8 guys get pushed to AAA depth, and our AAA depth becomes farther away AAA depth.

I'm also fine with Fitts, Criswell, Priester and Dobbings as our AAA depth, but not our 5th SP'er going into 2025. If I had my way, they be our 7-8-9-10 starters with Crawford as our #6/ long man.