The Dodgers started catcher Yasmani Grandal in three of their five postseason games in 2015. Hindsight being 20/20, it was three games too many.
At some indeterminate point in the second half of the 2015 season Grandal injured his left shoulder. From August 1st until the end of the season he put up a 37 wRC+ and a .064 ISO, a far cry from the 128 wRC+ and .181 ISO he had carried up until that point in his career.
The offseason came and Grandal went under the knife to fix his shoulder. Having experienced the power drop-off that came in the aftermath of Matt Kemp’s torn labrum in 2012, Dodgers’ fans were understandably nervous. A silver lining appeared however as it was determined by team physician Dr. Neal ElAttrache that Grandal’s AC joint was the problem and he was not facing a torn labrum repair. This revelation probably saved him an extra three months of rehab time.
Cut to 2016, where Grandal’s numbers have reached both incredible lows and prodigious highs. The rollercoaster of production could easily be pinned on his offseason shoulder surgery, but it’s important to remember that unlike Matt Kemp and Adrian Gonzalez before him, Grandal’s AC joint required no repair, just clearing out of bad tissue. It was a piece of good fortune in an otherwise regrettable situation because as Dr. ElAttrache told Peter Gammons, those who undergo labrum repair have an especially difficult time regaining their old swing.
"Trying to re-establish ones mechanics after surgery is a complex process," says Dr. ElAttrache, speaking generally. "It’s extremely delicate. It involves rebuilding strength, and all that goes into the swing from the front shoulder. It takes perfect mechanics to regain bat speed and the swing path. Sometimes it takes a year, sometimes more."
After dodging the bullet of labrum repair, Grandal posted a 152 wRC+ in 54 plate appearances in April to begin his 2016 season. A small sample to be sure (as any monthly split will be), but a good sign for his health nonetheless.
Catchers are never quite safe though. In early May while in Toronto, Grandal suffered a bone bruise after taking a foul ball off of his left wrist. To compound matters he took a foul ball off the ankle in a game in San Diego two weeks later. The Dodgers let him play through these injuries and his production suffered greatly.
|Aug (thru 8/12)||31||.500||.527||241|
As his wrist started to get better early in June, Grandal spoke to Mike DiGiovanna of the Los Angeles Times about how the wrist injury had been affecting his swing.
"While I was hurting, I was late on everything because my hands were slow," Grandal said. "But it’s gotten a little better. I don’t have to try to pull everything or swing harder. I just let everything flow, and that’s why I’m able to see the ball better. I’m swinging at better pitches and not chasing."
Taking a look at Grandal’s batted ball profile so far for 2016, the numbers show exactly what he was talking about.
|LD%||GB%||FB%||Pull%||Cent%||Oppo%||AVG Exit Velocity||AVG Launch Angle|
|2016: April-June||17.5%||53.2%||29.4%||42.1%||44.4%||13.5%||91.8 MPH||8.1°|
|2016: July-Present||17.5%||34.9%||47.6%||39.1%||35.9%||25.0%||94.9 MPH||17.0°|
Since getting over the wrist injury Grandal has reduced his ground-ball rate by just over 18 percentage points, changing all of those grounders into fly-balls. This is also illustrated in his drastic increase in launch angle. For a player who hits the ball hard but runs really slow like Grandal, this shift in batted ball tendencies is incredibly important, as Rob Arthur from FiveThirthyEight explains.
"At 94 miles per hour, a grounder is a net negative play for a slow runner, just about neutral for an average runner, and positive for the fast group. Because of this difference, low exit angles are much more harmful for lumbering first basemen than for speedy shortstops. The effect of speed starts to fade only when launch angles exceed 10 degrees, as exit velocity begins to take over as the biggest determinant of a batted ball’s fate."
When viewed in a heatmap of his ground-ball zone profile from Brooks Baseball, the difference from Grandal’s first three months of the season to now is jarring.
Despite the various injuries suffered while wearing the tools of ignorance, Grandal’s average exit velocity remained above league average (87 MPH as of 8/12). Once healthy he began to crush the ball even more consistently. Combined with that almost 9 degree rise in launch angle and it’s clear to see why Grandal is doing so much damage. A month and a half remains in the 2016 regular season and he has already eclipsed his previous career high in home runs (16), with 18 in just 331 plate appearances.
Check out Grandal’s isolated power heatmaps (courtesy of Fangraphs) from April through June compared to July to the present. Much like his ground-ball heatmap, the visual is jarring. He is now punishing pitches at both the top and bottom of the zone, a drastic change from prolonged slump of May and June.
It’s hard to pin Grandal’s struggles on his offseason shoulder surgery. The effect is certainly not null, but with the solid start to the season it's also not all that quantifiable. There does appear however to be a significant correlation between the wrist injury he suffered in May and the drop in production that followed.
Being a catcher, Grandal will always be one foul tip away from disaster, but for now he is healthy and raking. A key cog in the Dodgers' lineup as they continue to battle it out with the Giants for the NL West title, he is making his presence felt at exactly the right time.
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Chris Anders is a contributor to Beyond the Box Score. You can follow him on Twitter at @MrChrisAnders.