Gather, my children and you shall see / The mystery fastball of Jake McGee / Fastball if by land, and also fastball, by sea
The eleventh day of the Twelve Days of Free Agent Relief Pitchers is a magical day, children. It is unlike all other days, in that it is not only a profile of Jake McGee, but also the tale of an adventure through the sparkling snowy plains of Baseball Savant, overseen by three kindly spirits: Collette, Chase, and Fast.
If you are just joining me, I promise the articles that have brought us here are not nearly as weird as today’s:
- A brief review of some advanced metrics I cite
- First Day of RPs: Liam Hendriks
- Second Day of RPs: Brad Hand
- Third Day of RPs: Trevor Rosenthal
- Fourth Day of RPs: Kirby Yates
- Fifth Day of RPs: Trevor May
- Sixth Day of RPs: Joakim Soria
- Seventh Day of RPs: Blake Treinen
- Eighth Day of RPs: Alex Colome
- Ninth Day of RPs: Keone Kela
- Tenth Day of RPs: Justin Wilson
- Eleventh Day of RPs:
Not one of our twelve festive relief pitchers puzzled me like Jake McGee. Jake McGee is, in fact, culpable for this becoming a series of articles, and not a singular holiday-themed rundown. It was Jake McGee for whom I said: three hundred words will absolutely not suffice.
As you’ll discover if you go on this journey with me, solving one puzzle left another one in its wake. Looking at his Baseball Savant page is sort of like looking at an ambiguous image: is it a rabbit or a duck? Is it an old woman or a young woman looking out of the window?
The First Mystery: Hard Hit Rate vs. xwOBA
On the one hand, the hard hit rate and average exit velocity on batted balls versus McGee were amongst the worst in the league—he ranks in the 4th and 1st percentile, respectively. On the other hand, his xwOBA is in the 97th percentile, nearly the best in the league. I was raised* to believe that all of the expected stats were based on quality of contact, and it seems like the quality of contact McGee surrendered was poor, so these look contradictory. It led me to this Twitter conversation:
*Yes my life-span is during the Statcast era, who’s asking
The key to the First Mystery is Jake McGee’s astonishing 41.8% K rate, good for the 99th percentile. On the above Twitter thread, I got into a conversation with Alexander Chase, who sent me a link to his very excellent article on Pitcher List. He explains that the problem with hard hit rate stems from it being taken as a percentage of batted ball events, rather than batters faced. Consequently, it can penalize pitchers who strike batters out rather than allowing soft contact.
In McGee’s case, he’s giving up screaming contact, but he’s not allowing it very often, with a career-high strikeout rate. Meanwhile, considering his hard hit per nine innings, accounting for every ball over 95 mph by his inning total rather than by batted ball events, McGee had a 9.30 HH/9. This seems roughly average, according to the charts in Chase’s article, rather than the worst in the league.
The Second Mystery: The One-Pitch Pitcher
But if my goal in this series—and yes, you’re more than forgiven if you forgot that I had one—is to rank these relief pitchers for hypothetical future usefulness, with their past as a template for their future, McGee is again a conundrum, for two reasons.
The first is that he got to a career-high strikeout rate this year by throwing his fastball All. The. Time. That sounds like an exaggeration, but by the standards for truth in 2020, it’s basically a fact. He deployed the four-seamer 96.4% of the time, meaning that in a shortened season, he also threw exactly 10 sliders and 2 sinkers. Those aren’t percentages. Those are the number of times he threw those pitches: 320 fastballs, 12…other.
To watch McGee, he varies the location as he pitches, but the majority of his pitches land in the heart of the zone. This does explain why when a batter connects, it’s often smashed. With an average of 95 MPH, his fastball is above-average, especially for a lefty, but not necessarily overpowering.
Although I’d be remiss if I didn’t point out that 95 MPH represents an improvement over the past two seasons. McGee added an average of 1.5 MPH to his fastball from last year. However, this can’t be the only thing driving the pitch’s success, since his fastball has averaged as high as 97 earlier in his career, and he’s never had anywhere close to a 41.8% strikeout rate previously. In 2017, when his four-seamer averaged an identical 94.9 MPH, it still garnered a 19.4% whiff rate, versus a 34.2% on the same pitch in 2020.
The Third Mystery
And any examination of McGee’s track record, or career numbers, returns us to the ambiguous image analogy. How is this pitcher both a rabbit and a duck?
Because the Rockies did not get the rabbit they thought they were getting in a trade with the Rays, where McGee had a 1.89 ERA in 2014 and a 2.41 ERA in 2015, with FIPs that were even lower. Instead, duck-like,* his ERA was slightly over two points higher in his four years with the Rockies, at 4.78, than it was with the Rays, at 2.77. And his strikeouts—the key for McGee’s success, as we’ve seen, even more so than with any pitcher—mirror this. An 11.1 K/9 with the Rays shrank to an 8.2 K/9 with the Rockies.
*Everyone knows rabbits are better pitchers than ducks. It is objectively true.
But in his short 2020 season with the Dodgers, who signed him in July following the Rockies’ release, was more than a bounce-back to his numbers with the Rays. He came by a 2.66 ERA with a staggering 14.6 K/9. Obviously, the effects of the altitude at Coors Field are well known, but I thought of this as primarily making batted balls fly farther, and lessening the movement on breaking balls. McGee has always used his fastball as his establishing pitch, relying on it more heavily over the course of his time with the Rockies. Why would pitching in Colorado have affected him so much?
I Seek Help
No, not that kind, though I can see why you think I would need it.
Curious as to why a fastball-reliant pitcher might see such a reduction in strikeouts, I turned to my friend Alex Fast, who, amongst his long line of titles and baseball appearances, is VP of Pitcher List, and President of Putting Up with My Stupid Questions. Alex pointed to the active spin on McGee’s fastball, improving from 2019 to 2020 from 87.3% to 92.2%. According to my math from the active spin leaderboard, which may be fallible, that puts him from being just about league average—in the 51st percentile—to well-above average, in the 75th percentile.
As I’ve mentioned in other articles in this series, the effect of active spin for a fastball is that the pitch looks like it’s rising. This is where we get the term ‘rising fastball,’ even though that’s physically impossible. But this would help explain how McGee got so many strikeouts, even when pitching across the heart of the plate. Fast shared with me that he had a 29% swinging strike rate over the heart of the plate, which is a staggering number, and the first time he’d garnered more than 20% SwStr in that zone in his career.
The problem is, Baseball Savant doesn’t have active spin information posted for years prior to 2019. So, it’s impossible to look back at McGee’s days with Tampa Bay and be certain that this was spin he also had before moving to Coors, now regained. But it feels plausible, given the altitude’s other effects on pitches. And it makes more sense than anything else.
The Return of Collette
Of course, it still led to numbers never seen before in his career, in terms of that 29% SwStr in the heart of the plate, or the 41.8% K%. Coors can’t be the only explanation.
Fortunately, Jason Collette, whom you may recall from the Twitter exchange I highlighted in the First Mystery (aka “WTFuck”), wrote an excellent article about McGee after I had come to this detente in my conclusions. He explains that McGee doing exactly what I had observed—pounding the fastball relentlessly into the zone—forces the hitters to swing. Voila: strikeouts. “When a pitcher is attacking that part of the zone at a high frequency, and hitting his target,” Collette writes, “it forces the issue quickly in a count.”
As I said in my tweet, Jason is, in fact, smarter than me. I was caught in an assumption about pitching as a manipulation of changing speeds and eye-lines. But perhaps, to reverse the adage, McGee is playing checkers when everyone else is playing chess. And it’s working for him.
My Own Conclusions
And at the same time, I’m still ranking Jake McGee here, which is probably below where others would have him. Number Eleven is certainly not in keeping with his astonishing K% in 2020, which, as Alexander Chase writes in the piece that I cited above, is the most predictive stat for a subsequent season’s ERA. If that’s the case, that glorious 41.8% strikeout rate should have me all-in on Jake McGee.
I cannot deny that McGee was excellent in 2020. And I can’t deny that he got there by throwing 97% fastballs, 62% of which were in the zone. It worked. And hypothesizing that Coors Field had an affect on his ability to get strikeouts by limiting his fastball’s active spin helps explain his career’s fall and rise.
So, if his 2020 blueprint continues to work for him, he may well be more productive than other pitchers whom I’ve ranked more highly in this very, very serious, life-or-death holiday-themed free agent relief pitcher series.
But being a one-pitch pitcher, long-term, gives me pause. Can his performance in 20 innings this year be replicated? It seems like batters will adjust to this approach in a longer season, even if it’s not 162 games, and we’ll get more of those hard-hit balls on middle-middle pitches. Call it my chess-over-checkers bias. I don’t care. It’s Beth Harmon’s world, and we’re all just living in it.
Oh right, free agency
At 34, Jake McGee hits the market a second time. His age may decrease his value to clubs, as they perambulate down the relief pitcher aisle. On the other hand, after all of my circumnavigation, he’s still a lefty with reverse career splits (.222 AVG against from righties; .248 for lefties). FanGraphs’ crowdsourcing projects a 1 year, $5 million deal. Some team could get a bargain; at that price, even I might have the guts to be the one.
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