Eduardo Rodríguez is an Ace
Photo by Chris Coduto
Let’s just start with Eduardo Rodríguez’s weird statcast page:
Eduardo Rodríguez’s Statcast card.
Bad strikeouts, bad whiffs, bad velocity, okay ground balls, nothing that screams 2.50 ERA in 162 innings. Weird.
Rodríguez has been the ace in what’s been a bit of a down year for the Arizona Diamondbacks pitching staff. The team is 72-64 given their effective offense powered by Corbin Carroll, but the pitching has been a struggle. 2021 NL Cy Young winner Corbin Burnes is still injured, Zac Gallen is both injured and ineffective when he is on the mound, Ryne Nelson and his outlier fastball is on the 60-day, Michael Soroka hit the 15-day yet again this season. The Snakes are umm… hurt. Rodríguez has posted every 5th day for the D-Backs as their left-handed saving grace.
On the surface, nothing is particularly special about Eduardo. He’s mostly throwing a fastball/changeup with below average velocity and an effective cambio. It’s the 10th best changeup in baseball by Run Value. His most recent outing was for 7.0 innings and 2 hits against the Cubs, and that’s kind of been the story of his season. He’s never gone out for more than 5 earned runs this season and only has one real blowup against the St. Louis Cardinals back in July. The rest of the season has been frankly remarkable. His outings have been worth as many as Mason Miller, Tarik Skubal, and Shohei Ohtani for 21 Pitching Runs.
Eduardo Rodríguez’s sequencing by Baseball Savant
Eduardo’s changeup usage ramps up when he’s in equal counts or pitching ahead. Right-handed hitters are all but guaranteed to see a changeup at least once in a given at-bat, and they still can’t hit it. He’s doing all the little things right, including posting a first-pitch strike% of 61.7. I’ll skip the boring part where I analyze all the zone swing numbers, but the short version is that he’s forcing aggressive swings over the plate (likely due to the fact that he isn’t exactly throwing 100 mph) while inducing a 1.8% in-zone whiff rate above league average. That doesn’t sound like much, but Zack Wheeler is inducing whiffs at around this level inside the zone.
Eduardo, despite roughly league-average Stuff+ marks, is enjoying a 109 Location+, which is invariably good. Every pitch except his sinker has marks at least 7 points better than league average, with his four-seam as the star of the show at the top of the zone:
Eduardo Rodríguez locations by Statcast
A college pitcher would kill for locations like this. You can see his four-seamer riding well into the top of the zone, a dotted cutter for lefty hitters, and the changeup low and away. The curveball is frequently placed on a picture-perfect bottom corner for a stolen strike. This has to be art somehow.
The 33-year-old effectively turns over lineups time and time again, beating the league’s best offense with a soft heater even for lefty pitchers. I’ve sat down to write about today’s lefty multiple times and honestly struggled to generate real insight as to why his ERA is nearly a full two runs below expectations. Honestly, I firmly expected serious blowups after his April/May dominance. Usually my thoughts about pitchers are slightly formulaic. I usually look for a given pitcher to check two of three* boxes: missing bats, lowering walks, and preventing hard contact. I put an asterisk next to “three” reasons because there are analytical outliers—arms whose Statcast cards don’t immediately describe what they do and don’t do well. Eduardo Rodríguez is one of those along with names like Martín Pérez, Andrew Abbott, and Justin Wrobleski. These pitchers make my job fun.
Our answer behind Rodríguez’s sustained success lies in his 4-Seam, which ironically is good for four reasons:
Rodríguez is left-handed, and stands on the third-base side to create a difficult angle for righty hitters who just can’t seem to pick up on the direction the heater is coming from given his high slot. Think of Chris Sale starting his arm action physically behind a left-handed hitter. Geometry!
Left-handed pitchers are just fundamentally hard to hit sometimes too.
League-wide xpected line vs RHP: .245/.321/.399
vs LHP: .240/.316/.385.
On the surface, that’s not a major improvement, but it should be kept in mind that LHPs usually throw about 2 mph slower on average, which usually generates aggressive shifts in batting lines (ie. facing 97 mph instead of 95).
Then there’s the fun stuff.
Like I said, Rodríguez has a remarkably effective changeup. He’s only given up four homers on it all year, fewer than Yoshinobu Yamamoto has on his World-Series level splitter (6).
The changeup is tunneling extremely well off the fastball given his arm slot similar to the wild swings that Skubal generates on his offspeed. Hitters are forced to respect his heater at the top of the zone given that it might suddenly disappear at 85 mph into the dirt. It’s kinda hard to hit a pitch if you’re flailing over it:
Eduardo Rodríguez’s changeup bat tracking by Statcast
For arms like Rodríguez, the changeup feeds off the heater playing well and vice versa, leading to an endless cycle of “late on heater, early on changeup” that ruins a lineup’s evening.
Stuff+ also doesn’t seem to be respecting the approach angle for the lefty either, which is -5.0o, which furthers the illusion that his fastball is “rising” into the top of the zone. Didier Fuentes has created closer-or-starter arguments in the Atlanta clubhouse by throwing his heater at a -3.9o angle good for a 31% K rate despite 69% heater usage. Rodríguez is using the exact same principle to airlift his fastball to the top of the zone and destroy a hitter’s perception of exactly how the fastball is approaching the top of the zone. Here is a decent look at this effect in a Bryson Stott at-bat against that Shohei guy.
Photo by Sue Ogrocki for the AP
Rodríguez is a key for Arizona as they look to nab the third Wild Card spot from the Padres, and he isn’t just enjoying a nice hot streak because every hitter is topspinning the ball at Geraldo Perdomo. No, Eduardo Rodríguez is doing absolutely everything right for a pitcher who doesn’t prevent every walk, hard-hit ball, or baserunner. Rather, he depends on his quietly elite fastball shape and strong changeup to give the Diamondbacks length every time out, almost always to the tune of a quality start.
About the Author: Ransom Fassett is a Sabermetrics writer for Painting Corners, you can find more of his work here.