In our season preview, I wrote about how Masahiro Tanaka had to make a huge adjustment to his splitter halfway through last season. Due to changes in the baseball, Tanaka changed the way he gripped his signature pitch. With a full offseason (plus a few months) to continue fine tuning, I figured it was worth looking into what the crafty Tanaka has come up with for his splitter so far this season.
In just three starts, Tanaka has had great success with his splitter. Batters are hitting a lowly .176 against the pitch after hitting .287 against it last year. Batting average, of course, isn’t everything, and the predictive metrics are also good. Batters have an xwOBA (expected weighted on-base average) of .246 against Tanaka’s splitter this year compared to .310 last year. Moreover, the exit velo on the pitch is down to 85.5 mph after reaching a career high of 88.9 mph last year. So far, so good. Crucially, according to FanGraphs pitch values, Tanaka’s splitter has already been worth 2.1 runs. With his struggles last year, the pitch was actually worth -5.7 runs.
Interestingly, the pitch hasn’t changed the way you would expect it to based on that improvement. For pitches that drop like a splitter, they are normally most effective with low spin rates and high vertical drop. Tanaka’s issue last year was that the pitch had a higher spin rate and less vertical drop. That was what led to many splitters over the heart of the plate hit for home runs.
This year, Tanaka’s spin rate on the splitter is actually even higher. Take a look:
Likewise, there is even less vertical break than in the past. So what’s been the difference? Location.
This side-by-side shows Tanaka’s 2020 splitter locations (left) compared to 2019 (right)
For 2020, you can see Tanaka pounding the lower part of the zone for called strikes and throwing it right below the zone to induce weak contact or swings and misses. Compare that to 2019 where you see a lot more variation in the pitch location as well as many more over the heart of the plate.
So even with the reduced vertical movement, Tanaka is throwing the pitch where he wants to. And maybe that is the difference – with more time to adjust to his new grip and reality, Tanaka being the pitching guru that he is figured out how to throw his splitter where he needs to.
Of course, with only three shortened starts under his belt, everything in this post has a small sample size caveat, but so far the early returns on Tanaka’s splitter have been encouraging. Look for him to continue that success against the Rays tonight.