Your Team Should Sign Masahiro Tanaka
After the departures of Marcus Stroman, Charlie Morton, Drew Smyly, and Mike Minor, the starting pitching market is thinning fast. The ‘Bauer-or-bust’ mentality has only intensified as a result. But should it? There’s a pitcher who may provide as much per-dollar value as Bauer, albeit with less of a ceiling. His name is Masahiro Tanaka.
Let’s cut straight to the chase. What are some upsides to signing Tanaka? One is durability. Tanaka is one of just 32 starting pitchers to accumulate 1000+ innings since 2014, when he made his MLB debut. He’s contributed at least 150 innings per season, except for 2014 and 2020, without major injuries. His ERA and FIP are on the lower side among those 32, but by fWAR he’s ranked 18th with 18.9. Tanaka’s been incredibly consistent for a while, and in times of uncertainty, that alone makes him stand out.
You probably already knew that. But examining his pitch arsenal gives us a better idea of what kind of pitcher Tanaka is — and could — be.
Earlier this year I wrote about how in his first start of 2020, Tanaka threw his fastballs 58.8% (!) of the time and almost exclusively up. The fastball rate has dwindled since then, but he’s continued to live up in the zone. Check out how the heat maps have changed from 2019 to 2020:
Did doing so produce results? Absolutely! The whiff rate on his four-seamer has nearly doubled, from 17.3% to 30.1%. High fastballs work: Even a pitcher like Tanaka, whose spin rate and subsequent vertical break on his own are average at best, can limit contact by adopting them.
The fastball itself has also improved, gaining a few ticks of active spin and helping it return to 2018 levels of vertical break:
Tanaka isn’t deteriorating with age — in fact, he’s evolving. Some of his efforts weren’t validated, however. Despite a more optimized fastball, the xwOBA against it jumped from .405 to .448, or poor to almost disastrous. But I’m far from concerned. Think of this way: Either the changes are eventually reflected in on-field results, or Tanaka continues to get pummeled. Which of the two is more likely to repeat itself?
It’d be remiss to write an article about Masahiro Tanaka and not include his slider. Its usage has gradually crept up since 2015, overtaking his former signature splitter and reaching 37.7%, a career high, in 2020. Overusing a secondary pitch can sometimes backfire, but in Tanaka’s case, his slider is genuinely great. In any given year, the pitch usually produces the lowest xwOBA and highest whiff rates of his entire arsenal.
Tanaka threw markedly less sliders this year due to circumstances, but they still looked fantastic. As evidence, here’s a comparison of a few key pitching metrics by year:
Yep, those are good numbers. What’s interesting is how Tanaka’s CSW rate in 2020 compared to that of more renowned pitchers. Dinelson Lamet, the Padres’ slider king? His CSW rate was 40.4%, only a step or two ahead of Tanaka’s. How about Jacob deGrom? At 36.9%, Tanaka beats him with ease.
This isn’t a competition, of course, but it goes to show that we shouldn’t be underrating the veteran’s slider! There’s more to the slider than just CSW rate, however, because while the results have been consistent, the movement imparted to it has not. First, here’s a slider from 2019:
Next, here’s a slider from 2020:
Same batter, same location. The difference is subtle, but it’s there. The 2019 rendition veers outwards from Vlad Guerrero Jr., whereas the 2020 one features a more straightforward drop-off. Consulting a pitch movement chart confirms these observations:
How would we characterize this shift? Tanaka’s slider in previous years resembled a sweeping slider –– lots of horizontal movement, minimal vertical movement –– but now has moved closer to a gyro spin slider, which aims to minimize any sort of movement. That seems counterintuitive, but by doing so the slider receives the full force of gravity, creating a trajectory that could deceive a hitter.
This is also reflected in its active spin rate, which has dropped from 30.7% to 21.0%. Since more active spin means more spin that contributes to a pitch’s movement, an ideal gyro spin slider would have as minimal active spin as possible. Tanaka is heading in the right direction, but he’s not quite there yet. Perhaps he was in the midst of working on it with the Yankees staff.
But even if Tanaka returns to his old slider, it’ll still remain plus pitch. Besides, his work on both the fastball and slider is maybe a sign of an intangible quality –– that Tanaka is willing to make adjustments despite his veteran status.
Masahiro Tanaka isn’t a pitcher who instantly comes to mind for many, but he’s an excellent option for any team. He’s on the cusp of decline, sure, but some aspects of his game are resistant to the force of age. For example, a pitcher’s walk rate is consistent throughout his career, and Tanaka regularly ranks in the 90th percentile or higher in BB%. And a drop in velocity won’t be as detrimental if he continues to thrive up in the zone.
As for the per-dollar value bit I mentioned earlier? Steamer projects Bauer to put up 3.8 fWAR in 2021. Tanaka is pegged at 3.0. If you consider the type of deal each player will likely receive, perhaps that isn’t such an outlandish claim.
All data from Baseball Savant, FanGraphs, and TexasLeaguers.com.
