While there have been a number of compelling storylines surrounding the 2020 season, none have been as fun as the San Diego Padres. Built around what appears to be a generational talent in Fernando Tatis Jr, the Padres were one of the most active teams at the deadline. Their incredibly talented offense has helped to push them into playoff contention and their additions seem to be targeted at filling holes. However, despite all of their success, their budding ace Chris Paddack has struggled mightily in 2020. After finishing second in the Rookie Of The Year vote, Paddack appeared destined to be a frontline starter for years to come. Yet so far in 2020, he has struggled mightily seeing his ERA jump to 4.4. Let’s take a look at his location data to see if there is an explanation for his struggles.

Chris Paddack

As has become customary for me, the first thing I like to look at with pitchers is a change in pitch mix. Paddack however, seems to have no such change. He heavily features two pitches, a fastball and a devastating change-up. He also mixes in enough curves to keep hitters honest. However, there are no major differences in usage. Yet, what jumps off the page looking at his Statcast numbers is how hard is fastball is being hit. After allowing a sub .300 xwOBA in 2019 with the fastball, that number has jumped to well over .400 according to Baseball Savant. The change-up seems to be getting similar results so the question is, what has changed?

With something like this, my first check is always how the location plot looks. As we can see with Paddack he does not appear to be locating the pitch horribly. While there is a decent amount of pitches overlapping with dark red portions of the plots, fastballs in general get hit pretty hard. The averages show this as well. Paddack’s location-based xwOBA is middle of the pack for all pitchers with at least 200 fastballs thrown. Actually his xWhiff is 10th best in all of baseball in that same sample. So, it appears that the location of the pitch does not appear to be the issue.

So what gives? How did this great fastball from a year ago turn into an extremely hittable pitch? Well the answer may also appear on his Savant page.

The line we care about here is the red line. His fastball last season average two inches more vertical movement than average and this season is also moving less than the average fastball. These averages come from using pitches with similar velocities and release/extension. This is a massive change. Vertical movement on the fastball has become all the rage in recent seasons for good reason. It is one of the most important factors in swinging strike rates for fastballs. Looking into some quick surface numbers there does not appear to be a difference in spin rate. However, there is a small difference in release point compared to 2019. This leads to believe he may not be getting on top of the fastball as well as he did last year leading to a small change in the spin profile. According to Brooks Baseball, there is a small spin axis change that could be accounting for this. Overall, this is a very minor difference but it shows how thin the margin for error is with fastballs. Even seemingly elite ones can get hit hard is their underlying characteristics are modified slightly. I’ll be watching to see how Paddack’s vertical movement on the fastball changes the remainder of the season. If he does seem to get the vertical action back on his fastball I’ll be trying to buy him this offseason in Dynasty.

Stuff ERA Leaders

 

Stuff-ERA Leaders
Min 300 Pitches
Pitcher Stuff-ERA
Shane Bieber 2.5191
Jacob deGrom 2.6889
Yu Darvish 2.6940
Kenta Maeda 2.9006
Zac Gallen 3.0237
Corbin Burnes 3.0581
Dinelson Lamet 3.0721
Dylan Bundy 3.1181
Max Fried 3.2035
Aaron Nola 3.2180
Zack Greinke 3.2343
Scott Barlow 3.2656
Lucas Giolito 3.3242
Zach Davies 3.3408
Lance Lynn 3.3482
Freddy Peralta 3.3509
Trevor Bauer 3.3554
Frankie Montas 3.4107
Walker Buehler 3.4621
Ryan Yarbrough 3.5010
Gerrit Cole 3.5202
Sonny Gray 3.5680
Tyler Mahle 3.5718
Clayton Kershaw 3.5870
Adam Wainwright 3.6110
Ryan Castellani 3.6221
Dallas Keuchel 3.6342
Pablo Lopez 3.6554
Max Scherzer 3.6597
Jesus Luzardo 3.6641
Andrew Heaney 3.7525
Alex Cobb 3.7780
Framber Valdez 3.7893
Blake Snell 3.8054
Masahiro Tanaka 3.8141
Spencer Turnbull 3.8322
Dustin May 3.8328
Brandon Woodruff 3.8572
Josh Lindblom 3.8608
Lance McCullers Jr. 3.8638
Brandon Bielak 3.8727
Randy Dobnak 3.8877
Chad Kuhl 3.8926
Jose Berrios 3.8931
Julio Urias 3.9151
David Peterson 3.9159
Tyler Glasnow 3.9236
Kevin Gausman 3.9366
German Marquez 3.9374
Touki Toussaint 3.9396
Yusei Kikuchi 3.9464
Taylor Widener 3.9490
Kyle Hendricks 3.9511
Brad Keller 3.9677
Justus Sheffield 3.9703
Merrill Kelly 3.9803
Hyun Jin Ryu 3.9863
Tyler Anderson 3.9886
Zack Wheeler 3.9913
Elieser Hernandez 4.0000
Nate Pearson 4.0251
Jordan Montgomery 4.0397
Luis Castillo 4.0679
Alec Mills 4.0792
Jon Gray 4.0917
Logan Webb 4.1134
Brady Singer 4.1144
Aaron Civale 4.1438
Matt Shoemaker 4.1604
Chris Bassitt 4.1610
Carlos Carrasco 4.1614
Antonio Senzatela 4.1649
Daniel Ponce de Leon 4.1709
Mike Minor 4.2686
Cristian Javier 4.2716
Tanner Roark 4.2728
Trevor Richards 4.2853
Martin Perez 4.2951
Mike Clevinger 4.3156
Danny Duffy 4.3267
Kolby Allard 4.3285
Marco Gonzales 4.3364
Tommy Milone 4.3757
Wade LeBlanc 4.3909
Robbie Ray 4.4045
Charlie Morton 4.4216
Alex Young 4.4283
James Paxton 4.4304
Kyle Freeland 4.4339
Colten Brewer 4.4425
Garrett Richards 4.4474
Taijuan Walker 4.4680
Patrick Corbin 4.4783
Dylan Cease 4.4841
Gio Gonzalez 4.4987
Johnny Cueto 4.5074
Kyle Gibson 4.5595
Matt Andriese 4.5895
Nick Margevicius 4.5964
Zack Godley 4.5966