wPDI for Relief Pitchers: Mid-August Update

Previously, I provided the mid-August Weighted Plate Discipline Index (wPDI) update for starting pitchers. We took a deeper look at some rookies and comeback players found atop the wPDI leaderboard. Players such as Brendan McKay, Zac Gallen and Dinelson Lamet were highlighted by their deceptive repertoire.

Now it’s time to tackle the relief pitchers.

You can find the definitions and indexes of wPDI in its introductory article, found here. Here is a quick reminder on what the six possible plate discipline outcomes look like:

Classifying the 6 Pitching Outcomes
Outcome Outcome Outcome Outcome Outcome Outcome
Zone? Out of Zone Out of Zone Out of Zone In Zone In Zone In Zone
Swing? Swung On Swung On No Swing Swung On Swung On No Swing
Contact? No Contact Contact Made No Swing No Contact Contact Made No Swing

Let’s take a look at the 2019 year to date wPDI leaderboards, for relief pitchers [minimum 15 IP]:

Relief Pitcher 2019 wPDI Leaderboard
Name IP wPDI
Andrew Kittredge 27.0 .401
Ryan Pressly 45.3 .395
JT Chargois 18.0 .395
Josh Hader 55.3 .389
Amir Garrett 44.7 .387
Adam Morgan 29.7 .387
Ken Giles 37.0 .386
Hector Neris 48.7 .386
Austin Adams 24.3 .385
Jake Diekman 45.0 .384
Sergio Romo 43.3 .384
Colin Poche 32.0 .383
Robert Stephenson 46.0 .380
Lucas Sims 22.0 .380
Will Smith 50.3 .380
Brad Hand 47.3 .376
Giovanny Gallegos 55.0 .374
Andrew Miller 38.0 .372
Joe Jimenez 44.3 .372
Evan Marshall 32.7 .371
Brandon Workman 51.7 .371
Chad Sobotka 26.0 .371
Emilio Pagan 49.0 .370
Nick Anderson 48.7 .370
Tommy Kahnle 48.3 .370
Pedro Strop 28.7 .369
Noe Ramirez 48.7 .369
Scott Barlow 46.0 .368
Kirby Yates 46.7 .368
Matt Wisler 39.3 .366
Zac Rosscup 18.0 .364
Kenley Jansen 45.7 .363
Tony Watson 45.0 .361
Seunghwan Oh 18.3 .360
Corbin Burnes 46.0 .360
Alex Claudio 47.7 .360
Yoshihisa Hirano 43.0 .360
Luke Jackson 53.0 .360
David Hernandez 42.7 .359
Edwin Diaz 44.0 .359
Oliver Perez 31.0 .359
Raisel Iglesias 50.3 .358
Tim Mayza 44.0 .358
Wandy Peralta 32.0 .357
Matt Barnes 44.3 .356
Adam Ottavino 52.0 .356
Mychal Givens 45.3 .356
Oliver Drake 29.0 .355
Kyle Crick 42.0 .354
Jordan Hicks 28.7 .354
Minimum 15 IP

Let’s dive into some detail for a few of the players at the top of the wPDI leaderboard:

Andrew Kittredge (.401 wPDI)

Andrew Kittredge of the Rays, sits atop all of baseball with a .401 wPDI. Currently, he has a 3.33 ERA with 36 Ks in 27 IP – a K/9 of 12 (K% of 32%). ERA estimators show that he has been unlucky – his xFIP is at a much better 2.79. He also has a .358 BABIP, which might mean that his 1.30 WHIP could be even lower.

In terms of plate discipline outcomes – Kittredge excels in the ABC outcomes, which are the out of zone binary possibilities. Andrew is getting lots of swings and misses outside the zone, while limiting his called balls. His outcome A is the 3rd best among relievers; the only players with a better outcome A are Ken Giles and JT Chargois.

JT Chargois (.395 wPDI)

Speaking of JT Chargois (.395 wPDI) – after finishing 2018 within the top 20 of relievers, JT once again finds himself in the elite wPDI discussion. After having a nice season last year with the Dodgers where he finished with a 3.34 ERA, Chargois has a 5.00 ERA in 18 IP this season. Like Kittredge, this may be also be the product of bad luck. JT’s SIERA is a robust 2.81, which more closely corresponds to his 1.17 WHIP. Chargois has increased his strikeout rate from an 11 K/9 in 2018 to a 13 K/9 this season.

Robert Stephenson (.380 wPDI)

With a .380 wPDI in 46 IP, Robert Stephenson is a plate disciple pitcher surprise. For Stephenson, his Outcome A is about as good as it gets. 13% of all pitches that he throws are out of the zone, swung on and missed. Stephenson also generates little contact in the zone (Outcome E) and throws few pitches out of the zone which are not offered at (Outcome C). He is an ACE wPDI pitcher!

Stephenson is currently sporting a 4.70 ERA, but wPDI thinks that he is due for a nice correction. Other ERA estimators concur. For example, his 2019 SIERA is over a full run lower at 3.57.

Ryan Pressly (.395 wPDI)

To me, the most impressive player on the leaderboard is Ryan Pressly (.395 wPDI), who was the 2018 MLB wPDI leader with a .401 wPDI. At a .395 mark this season, he is now sits as the 2nd best player in all of baseball. I wrote about Pressly’s dominance back in June – and since that time, he has remained fantastic. Ryan has a 1.99 ERA with a 0.88 WHIP on the season. He has only given up 9 walks yet struck out 57 batters in the 45 innings that he has thrown. Pressly is an elite reliever in baseball over the past two seasons, especially after being traded from the Twins to the Astros. The Astros are incredible at getting the most out of pitchers these days.

Hector Neris (.386 wPDI)

Finally, we come to Hector Neris (.386 wPDI), who I have not spoken about at all this year. Prior to the season, it was unclear who would assume the closer role for the Phillies. Newly signed David Robertson and fireballer Seranthony Dominguez were the favorites to win the job. Had we looked at his wPDI, we might have given more thought to Hector Neris as the possible Phillies stopper.

Neris finished 2018 with a .378 wPDI, which was good for the 9th best of all relievers. His ERA was an awful 5.10 last year, although that came along with the best strikeout rate of his career at 14 K/9. The luck pendulum has swung the other way in 2019, as Neris is sporting a 1.01 WHIP propped by a .240 BABIP. His true talent is likely somewhere in between the two seasons, but it is clear that he has the ‘stuff’ to close out games.

As for plate discipline outcomes, Neris excels at outcomes A, B & E. Outcomes B & E are the contact scenarios. What Neris is doing well at, is making sure that when a batter makes contact with his pitches – it is out of the zone. He still induces more contact within the zone, but it is only a 6% difference to the out-of-zone contact. Other pitchers who are similar in that regard include Sergio Romo, Evan Marshall and Pedro Strop.


We hoped you liked reading wPDI for Relief Pitchers: Mid-August Update by Ariel Cohen!

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Ariel was a finalist for two 2018 FSWA Awards - Baseball Article of the Year, and Baseball Writer of the Year. Ariel is the creator of the ATC (Average Total Cost) Projection System. Ariel also writes for CBS Sports and Sportsline, and is the host of the Great Fantasy Baseball Invitational - Beat the Shift Podcast. Ariel and his fantasy partner, Reuven Guy, have used the ATC system projections to finish in the money in several NFBC, RTSports, Doubt Wars and other national leagues, racking up several division titles. Ariel is a member of the inaugural Tout Wars Draft & Hold League. Ariel Cohen is a fellow of the Casualty Actuarial Society (CAS) and the Society of Actuaries (SOA). He is a Vice President of Risk Management for a large international insurance and reinsurance company. Follow Ariel on Twitter at @ATCNY.

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Ryan Brock

Outside Pressly, it’s a good list of guys with homer problems…