Weighted Plate Discipline Index (wPDI): 2019 Review

In my previous article, I gave an update on my Weighted Plate Discipline Index (wPDI) metric. wPDI arises from the core ingredients of plate discipline – looking only at zone rates, swing rates and contact rates.

An important distinction regarding wPDI, is that its sample size is quite a bit larger than other statistics. Many other stats are based on innings pitched, or even per plate appearance. The denominator of wPDI is pitches. While batter outcomes such as strikeouts and walks stabilize fairly quickly, wPDI can work even faster.

Let’s now take a look at the 2019 leaderboards for wPDI, to see if we can find some undervalued players.

Starting Pitchers

Starting Pitcher 2019 wPDI Leaderboard
Name IP wPDI
Blake Snell 107.0 .380
Chris Sale 147.3 .379
Gerrit Cole 212.3 .374
Justin Verlander 223.0 .373
Stephen Strasburg 209.0 .370
Zac Gallen 80.0 .365
Mike Clevinger 126.0 .362
Yu Darvish 178.7 .359
Max Scherzer 172.3 .358
Kenta Maeda 153.7 .357
Charlie Morton 194.7 .357
Lucas Giolito 176.7 .356
Patrick Corbin 202.0 .355
Luis Castillo 190.7 .355
Aaron Nola 202.3 .355
Kevin Gausman 102.3 .353
Jacob deGrom 204.0 .353
Collin McHugh 74.7 .353
Shane Bieber 214.3 .352
Jose Berrios 200.3 .352
Kyle Gibson 160.0 .350
Andrew Heaney 95.3 .350
Chris Archer 119.7 .350
Dylan Bundy 161.7 .348
Felix Pena 96.3 .348
Zack Greinke 208.7 .348
Robbie Ray 174.3 .348
Matthew Boyd 185.3 .347
Domingo German 143.0 .347
Joshua James 61.3 .347
Hyun-Jin Ryu 류현진 182.7 .347
Carlos Carrasco 80.0 .346
Jack Flaherty 196.3 .346
Dinelson Lamet 73.0 .346
Sam Gaviglio 95.7 .346
Jose Urquidy 41.0 .344
Tommy Milone 111.7 .343
Rich Hill 58.7 .343
Griffin Canning 90.3 .342
Kyle Hendricks 177.0 .342
James Paxton 150.7 .342
Sonny Gray 175.3 .340
Eduardo Rodriguez 203.3 .340
Frankie Montas 96.0 .340
Walker Buehler 182.3 .340
Freddy Peralta 85.0 .340
German Marquez 174.0 .339
Brendan McKay 49.0 .339
Francisco Liriano 70.0 .339
Trevor Bauer 213.0 .338
Miles Mikolas 184.0 .337
Alex Young 83.3 .337
Carlos Martinez 48.3 .336
Chris Paddack 140.7 .336
Ross Stripling 90.7 .335
Mike Minor 208.3 .335
Clay Buchholz 59.0 .335
Michael Pineda 146.0 .333
Noah Syndergaard 197.7 .333
Masahiro Tanaka 182.0 .333
Austin Voth 43.7 .333
Joe Musgrove 170.3 .333
Trevor Richards 135.3 .332
Gio Gonzalez 87.3 .332
Thomas Pannone 73.0 .332
Clayton Kershaw 178.3 .332
Tony Gonsolin 40.0 .331
Jake Odorizzi 159.0 .331
Caleb Smith 153.3 .331
Mike Soroka 174.7 .331
Max Fried 165.7 .330
John Gant 66.3 .330
Madison Bumgarner 207.7 .330
Minimum 40 IP

Above is the 2019 wPDI leaderboard for starting pitchers.

Blake Snell lead all starting pitchers in wPDI in 2019. The key to Snell’s success was his “out of the zone” plate discipline. In particular, Snell’s Outcome A (out of the zone, swung on and missed) was the 2nd highest of all qualified pitchers in baseball. In 2019, Blake produced a K% rate of 33.3%, the highest of his career. He logged a whopping 147 strikeouts in just 107 innings pitched. Both FIP and xFIP (3.32 & 3.31 respectively) agree that his 4.29 ERA last year was somewhat unlucky.

The health of Snell is a concern for fantasy owners, but if healthy – Blake Snell is a very undervalued asset, as substantiated by wPDI.

One elite wPDI pitcher to point out is youngster Zac Gallen. Gallen was traded mid-season from the Marlins to the Diamondbacks, swapped for prospect Jazz Chisholm. After dominating AAA earlier in the year with a 1.77 ERA, 0.71 WHIP and a K% of 33.6%, Gallen continued to shine at the major league level. He struck out 96 batters in 80 innings, compiling a sparkling 2.81 ERA along the way.

Looking at Gallen’s plate discipline makeup, in contrast to Snell – it is his “in the zone” outcomes which make him elite. He had one of the highest Outcome F rates of any starter (in the zone, no swing), and a low combined total of Outcome D+E. In short – for pitches in the zone, he is generating few swings, and otherwise little contact.

Gallen still has more to develop. His walk rate rose starkly in the majors upon his promotion. He was a tad lucky last year with a .284 BABIP and an 84% strand rate, so expect his ERA to rise in 2020. All things considered, his deception and plate discipline give us a hope for continued success. Take a flyer on this wPDI maven.

Relief Pitchers

Here are the top wPDI relief pitchers of 2019:

Relief Pitcher 2019 wPDI Leaderboard
Name IP wPDI
Ryan Pressly 54.3 .401
Josh Hader 75.7 .392
Adam Morgan 29.7 .387
Jimmy Cordero 37.3 .387
Austin Adams 32.0 .384
Andrew Kittredge 49.7 .383
Nick Anderson 65.0 .383
Sergio Romo 60.3 .383
Hector Neris 67.7 .379
JT Chargois 21.3 .378
Robert Stephenson 64.7 .376
Oliver Drake 56.0 .376
Joe Jimenez 59.7 .374
Emilio Pagan 70.0 .374
Amir Garrett 56.0 .374
Jake Diekman 62.0 .372
Lucas Sims 43.0 .372
Ken Giles 53.0 .371
Edwin Diaz 58.0 .371
Will Smith 65.3 .371
Luke Jackson 72.7 .370
Matt Wisler 51.3 .368
Andres Munoz 23.0 .367
Kenley Jansen 63.0 .367
Colin Poche 51.7 .367
Tommy Kahnle 61.3 .367
Brandon Workman 71.7 .367
Evan Marshall 50.7 .366
Giovanny Gallegos 74.0 .366
Scott Barlow 70.3 .366
Jonathan Loaisiga 31.7 .365
Buddy Boshers 20.0 .365
Noe Ramirez 67.7 .365
Brad Hand 57.3 .364
Zac Rosscup 18.0 .364
Wandy Peralta 39.7 .364
Kirby Yates 60.7 .363
Corbin Burnes 49.0 .362
Cody Stashak 25.0 .362
Raisel Iglesias 67.0 .362
Chad Sobotka 29.0 .362
Aroldis Chapman 57.0 .361
Seunghwan Oh 오승환 18.3 .360
Chaz Roe 51.0 .360
Jake Jewell 26.3 .360
Andrew Miller 54.7 .360
David Hernandez 42.7 .359
Dominic Leone 40.7 .359
Liam Hendriks 85.0 .359
Jay Jackson 30.3 .358
Tyler Glasnow 60.7 .357
Roberto Osuna 65.0 .356
Randy Dobnak 28.3 .356
Tony Watson 54.0 .356
Tim Mayza 51.3 .355
Yoshihisa Hirano 53.0 .355
Matt Barnes 64.3 .355
Minimum 15 IP

In 2019, Ryan Pressly led all of Major League Baseball in wPDI at .401! Do you know who led the MLB in wPDI in 2018? None other than Ryan Pressly with a .401 mark as well! After two years of dominance, it is clear that the Astros pitcher has developed to an elite reliever.

What does Pressly do well? Everything! His Outcomes A (out of zone, swing and miss) and F (in-zone, no swing) are super-elite. Getting swings and misses out of the zone, and generating called strikes are the keys for deception and “stuff.” From March to May last year, in his first 26 innings, Pressly yielded only one earned run. He only issued just two walks in that span. Incredible!

Roberto Osuna might have a lock on the closer role in Houston, but Pressly is every bit as good, if not better. In this short season, Pressly could get save opportunities, and will most certainly help your fantasy squad’s ratios. Consider owning him in mono leagues, in deeper mixed leagues, and even in some 12-team formats. He won’t be expensive to purchase.

I mentioned above that Blake Snell had the 2nd highest Outcome A of all major league pitchers. Finishing at the top of the Outcome A list, and high up on the overall 2019 wPDI RP leaderboard is Reds reliever, Robert Stephenson.

There are so many aspects of Stephenson’s game to like. The former first rounder had nearly a 20% swinging strike rate last year, generating a 31% K% rate. His out pitch is his dominant slider, which he throws more than half of the time. Stephenson was somewhat lucky last year; his BABIP was a very low .230, but that does not affect his wPDI. Keep your eye on this surging Reds reliever.

Other honorable mentions at the top of the wPDI RP 2019 leaderboards include Josh Hader and Adam Morgan. Hader, we all know about – but I would like to call your attention to Adam Morgan. Morgan generated a ton of swings out of the zone (Outcomes A & B), and was able to get an elite number of called strikes (Outcome F).

Year on Year Risers

Let’s take a look at the pitchers exhibiting the most improvement in their plate discipline metrics. Below are the biggest risers in wPDI for starting pitchers from 2018 to 2019 (min 40 IP in 2019):

Starting Pitcher 2019 wPDI Risers
Name 2019 IP 2019 wPDI 2018 wPDI YoY Change
Frankie Montas 96.0 .340 .295 +.045
Lucas Giolito 176.7 .356 .311 +.044
Ariel Jurado 122.3 .296 .258 +.038
Sam Gaviglio 95.7 .346 .310 +.035
Martin Perez 165.3 .329 .294 +.035
Yu Darvish 178.7 .359 .328 +.031
Matthew Boyd 185.3 .347 .320 +.027
Ranger Suarez 48.7 .324 .299 +.025
Gerrit Cole 212.3 .374 .349 +.025
Luis Perdomo 72.0 .327 .303 +.024
Kevin Gausman 102.3 .353 .329 +.024
Joe Ross 64.0 .320 .296 +.024
Kyle Gibson 160.0 .350 .326 +.024
Dillon Peters 72.0 .326 .302 +.024
Mike Clevinger 126.0 .362 .338 +.023
Eduardo Rodriguez 203.3 .340 .318 +.022
Tyler Chatwood 76.7 .316 .295 +.021
Stephen Strasburg 209.0 .370 .349 +.021
Lance Lynn 208.3 .322 .303 +.020
Blake Snell 107.0 .380 .361 +.019
Clayton Kershaw 178.3 .332 .313 +.019
Sonny Gray 175.3 .340 .322 +.018
Jake Odorizzi 159.0 .331 .314 +.017
Minimum 40 IP in 2019

With his splitter, Frankie Montas was the single greatest wPDI gainer for starting pitchers. Montas exhibited a pitch mix change from year to year, which is likely the core of what led to his large jump. From wPDI’s view, Montas is a sleeper for 2020.

Lucas Giolito follows on the list, jumping into star territory. I am hopeful that those gains can stick in 2020. Monitor him in his first few starts to see if his wPDI has fully translated.

Here are the largest relief pitcher gainers from 2018 to 2019:

Relief Pitcher 2019 wPDI Risers
Name 2019 IP 2019 wPDI 2018 wPDI YoY Change
Jimmy Cordero 37.3 .387 .305 +.082
Kolby Allard 45.3 .305 .234 +.071
Tanner Rainey 48.3 .346 .284 +.062
Evan Marshall 50.7 .366 .309 +.058
Andrew Kittredge 49.7 .383 .328 +.055
Giovanny Gallegos 74.0 .366 .311 +.055
Luke Jackson 72.7 .370 .315 +.054
Robert Stephenson 64.7 .376 .324 +.052
Emilio Pagan 70.0 .374 .325 +.050
Jerry Blevins 32.3 .344 .296 +.049
Jeff Hoffman 70.0 .311 .263 +.048
Luke Bard 49.0 .334 .286 +.048
Matt Wisler 51.3 .368 .322 +.046
Oliver Drake 56.0 .376 .330 +.046
Trevor Gott 52.7 .307 .261 +.046
Matt Magill 50.7 .353 .308 +.045
Brandon Workman 71.7 .367 .322 +.045
Wandy Peralta 39.7 .364 .320 +.044
Zack Littell 37.0 .322 .280 +.042
Evan Phillips 28.0 .325 .286 +.040
Joe Jimenez 59.7 .374 .336 +.039
Austin Pruitt 47.0 .342 .304 +.038
Adam Morgan 29.7 .387 .349 +.038
Minimum 15 IP in 2019

Jimmy Cordero, who has bounced around a few organizations, finally found it on the South side of Chicago. On the White Sox, Cordero pitched to a 2.75 ERA and a 0.97 WHIP in 36 innings last year. A .387 wPDI is worth monitoring.

Another White Sox player – Evan Marshall, kicked up his wPDI into high gear. Marshall, who previously had little success in the major leagues, finally had some at the age of 29. He threw 50+ innings of 2.49 ERA ball. Perhaps the White Sox front office reads my column?

Check out Andrew Kittredge of the Tampa Bay Rays. The Rays felt confident enough to trade bullpen stud Emilio Pagan to the Padres this offseason, and Kittredge could be one of those reasons. In 49 IP in the majors last year, he struck out 58 batters – a K/9 of 10.5. He compiled a 4.17 ERA, but FIP/xFIP say that it was unlucky (3.56/3.25, respectively). His BABIP was also a high .336. He was fantastic in AAA before this year’s call-up. In the minors last year, he threw 37 innings for a 1.93 ERA and an 0.80 WHIP, with a staggering 55 strikeouts (13.2 K/9). In this short season, keep a close and early eye on Kittredge for save chances, and how he develops.

We hoped you liked reading Weighted Plate Discipline Index (wPDI): 2019 Review by Ariel Cohen!

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Ariel is the 2019 FSWA Baseball Writer of the Year. He is the creator of the ATC (Average Total Cost) Projection System. Ariel was ranked by FantasyPros as the #1 fantasy baseball expert in 2019. His ATC Projections were ranked as the #1 most accurate projection system in 2019. Ariel also writes for CBS Sports, SportsLine, RotoBaller, and is the host of the Great Fantasy Baseball Invitational - Beat the Shift Podcast (@TGFBI). Ariel is a member of the inaugural Tout Wars Draft & Hold league, a member of the inaugural Mixed LABR Auction league and plays high stakes contests in the NFBC. 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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elkabong
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elkabong

” If anything, Stephenson was unlucky last year; his BABIP was a dreadful .230!”

Lower is better for pitchers. I still love Stephenson, but this statement is backwards.

Edit: And by better, I mean “luckier”.