Griffin Jax Should Move to a Two-Pitch Mix

[NeverSeenATwinsPlayoffWin]

Jax is a really good reliever. He's in the 94th percentile in a number of important statcast stats like xwOBA, xERA, and xSLG. His ERA (as of 08/14) is below 3.00, and he's helped the Twins win more than he has not (0.5 WPA). His leverage index is quite high (1.67), and he has dealt with jams really well (7.5 base-out runs saved). Sure, he's had some rough patches, but so has Duran (as well as any human being who has thrown more than a full season of major league baseball). While he's been a very good setup man, I believe that some adjustments to his repertoire can turn him from "good 7th/8th inning arm" to "dominant 8th/9th inning arm."

When Griffin Jax debuted late in the 2021 season, most analysts and fans lauded the nastiness of his slider (now called a sweeper) and its ability to carry his arsenal. He's thrown his sweeper more times than any other pitch, and it's been extremely effective. In '22, his sweeper had a run value of seven (1.3 RV/100), and he's already up to a run value of eight in '23 (1.9 RV/100). It's been a dominant pitch.

Jax's four-seam fastball, while not as lauded as his sweeper, has been very effective since his move to the bullpen. Most of its effectiveness centers around velocity (~96mph), as it doesn't have elite spin rate. He locates it well, especially glove-side (in on LHB), which makes it an effective weapon against lefties and a good set-up pitch against righties. A high-velocity four-seamer is generally effective secondary, and although the pitch is still a work in progress ('23 has been his first year with a positive run value on that pitch), it greatly aids his effectiveness.

Jax's tertiary pitches are where he loses some of his zeal. It's hard to make the case that a pitcher relies on a 5-pitch mix to keep hitters off balance when he's using his primary pitch almost 60% of the time. He is not using a changeup 6% of the time to set up his sweeper, nor is his cutter (4%) a setup for his four-seamer. He uses his changeup, 2-seamer, and cutter a total of 20.1% of the time. His run value is negative on all three pitches, and his RV/100 is below two on both his changeup and 2-seamer. His 2-seamer is particularly atrocious; it only offers 18.2 inches of drop and 14.1 inches of run. For reference, Jordan Hicks creates more total movement on his sinker (in both the vertical and horizontal directions), despite it being an average of 4 mph faster. The average hitter against that pitch is basically post-call-up Eddy Julien, and it hurts Jax's ability to be effective. The run value stat estimates that Griffin Jax has given up three more runs than average due to his tertiary pitches, which would lower his ERA from 2.96 to 2.40 if he had not given up the three runs. In my mind, an ERA below 2.50 is good enough to be a set-it-and-forget-it closer, and I think the dominant-end-of-game-arm-Griffin Jax is much closer than many of his naysayers realize.

If Jax were to cut out two or three of these pitches, I think he would be much more effective. Elite relievers like Alexis Diaz (and his brother Edwin), Paul Sewald, Clay Homes, Josh Hader, Craig Kimbrel, Emmanuel Clase, Bryan Abreu, Jose Alvarado, and many others utilize two-pitch mixes relying on a fastball and a breaking ball. The Diazes, Sewald, and Abreu specifically utilize the four-seam/slider combo with very good returns. Having a two-pitch mix is very common for relievers, and Jax should not be discouraged from heading down this path. Jax should shrink his pitch mix to throw more four-seamers and sweepers, as they are, by far, his most effective offerings.

[DJL44]

Open question whether they would be as effective if everyone knew he only throws two pitches. Also worth investigating whether he throws the other offspeed pitches to lefties/righties more often.

I think ditching the two-seamer could help based on your data. Getting a better 3rd pitch would make the most difference.

[SwainZag]

I think we can all just hope that Jax works on that 3rd pitch as hard as he worked last offseason to add velocity.  This is only his 2nd season as a full time relief pitcher.  I don't think we have seen the best of Griffin Jax yet.

[wabene]

Geez this page is as red as my Irish uncle's face on St Patty's Day

 

[2wins87]

I don't think he needs 5 pitches but I strongly disagree with going to just 2.

His worst stretch was in May when he basically was just going with two pitches. He didn't give up hard contact on the sweeper but opposing teams seemed to be able to sit on it, spoiling a lot of good ones while spitting on the "chase" pitches. He just wasn't able to put hitters away. After mixing in his cutter he had a good stretch.

I'm not sure why he totally abandoned the cutter. I guess he probably thought it was too hittable, though it just seems like there were a couple lucky hits off of it.  The changeup, similarly, has been effective when he's used it but with worse than expected luck. I'm not sure he needs to be messing around with a two-seamer.

He could probably use refinement on his tertiary pitches, but I do think there is a point of diminishing returns with the sweeper.