Exit Velo Numbers Show How Shoulder Issues Hurt Addison Russell’s Offensive Performance

I slept weirdly on my shoulder a few weeks ago and it still hurts. Even picking up a bag can irritate what was once a rocket of an arm. Because of that discomfort, I can empathize with Addison Russell, who dealt with shoulder problems that haunted his 2017 season. And through my Statcast data, I can pinpoint the effects of said malady on Russell’s overall numbers.

Hitting pitches hard is good, right? Of course. But if your shoulder hurts, you might not be able to swing the bat quite as well and, as a consequence, your launch speed would decrease. That’s what might’ve happened to Russell.

Let me show you the possible effect of his weakened shoulder on exit velocity. I split the 2017 regular season into two-week intervals (biweek; code by stats wizard Jim Albert) and plotted every single one of Russell’s batted balls by exit velocity.  For example, a black dot that lines up to 100 means that particular batted ball was smacked at 100 mph.  Each big red dot is the average of that particular biweek.

You see that purple shaded box? That’s eight weeks of weakly hit batted balls, the “weak weeks.” That’s also eight weeks of sporadic days off because Russell’s shoulder was hurting. Notice how his exit velocity picks back up halfway through the season when his shoulder was getting healthier, just before he had to go on the DL with a bum foot.

Now, it’s also possible that Russell’s exit velocity was so low in the first half of the year because he was just getting smoked by pitchers. But you have to think that an injury to a hitter’s upper half would have an effect on his overall ability to swing a bat. And once the discomfort in that shoulder eased, his exit velocity picked up.

Let’s say those numbers from the second half are more indicative of the hitter Russell will be moving forward. That would be absolutely huge because his weighted on-base average was estimated to go up 15 points for every one mph increase in exit velocity.

So when that doubt regarding the shortstop’s prowess at the plate creeps into the back of your mind, just consider that we have yet to see the best of a fully healthy Addison Russell.