A Historian with Heat Maps: Nolan Gorman and the Power of Narratives

Editor's Note: Deebeedub went above and beyond with this FanPost about Nolan Gorman hitting high fastballs and I thought if you haven't seen it yet, you would probably enjoy it!

I’ll be honest: I’m in way over my head this time.

I don’t consider myself an "old-school" baseball fan. I appreciate the value of such new-fangled, high-falutin’ statistics as WAR and xOBA and Stuff+. I don’t yell at clouds when people talk about spin rates and pitch shapes. But at heart I’m a word guy whose occasional pieces about weird little aspects of Cardinals’ history rely on my reading of century-old newspapers rather than cutting-edge statistical evidence.

And yet, being a gentleman of a certain age, I take that business about remapping neural pathways by trying new things seriously. So today, rather than pile on the verbiage, I’m digging deep into the numbers to answer a question that nagged at me all season. Let me preface this by saying that I might be horribly misinterpreting the data, in which case I welcome your (polite) critiques and invite Blake to actually do justice to my topic.

I’ve blotted out most memories of the 2023 season, but I recall three storylines from Spring Training: The emergence of Jordan Walker and Masyn Wynn, the promise that we had enough duct tape and crazy glue to hold together the pitching staff, and the assurance that Nolan Gorman had learned how to hit pitches at the top of the zone.

Jordan Walker already inspired one of my fanposts, and I have no desire to write a single word about, say, James Naile . I do, however, want to explore that third storyline. Maybe you remember this? Cardinal Nation scrutinized Gorman’s Spring Training at-bats like a fortune teller reading tea leaves. Or maybe a crystal ball. I’ve never had my fortune told. Each foul tip at the top of the zone portended a breakout season. "At least he made contact!" was the narrative.

Then we stopped talking about it. Once the games began to count, the narrative quite understandably shifted from Gorman’s cromulence at handling high heat to the Redbirds’ crapulence on the field. But I’m still curious about whether he tamed that particular demon. And so, lord help me, I consulted heat maps.

Let’s ease into this numbers thing. By every measure, Nolan Gorman’s 2023 marked an offensive step forward. In 2022, his rookie season, he slashed .226/.300/.420, good for an OPS+ of 104 and a wRC+ of 105. Not bad for a twenty-two year old! In 2022, however, he slashed .236/.328/.478. That translates to a 117 OPS+ and a 118 wRC+. That’s better! The underlying metrics are good, too. Gorman’s barrel% jumped from 14.4% to 16.5%, and his hard hit% went from 43.3% to 48.5%.

I’m stalling. Did he improve his performance against pitches at the top of the zone? Let’s go to the maps, which it totally didn’t take me twenty minutes to figure out how to generate….

First let’s look at slugging, because power is Gorman’s game. The 2022 season is on the left, 2023 on the right.

It looks like Gorman’s gone from a guy who murders middle-middle pitches to one who also murders low pitches. But I also note the yellow creeping toward the top of the zone. That seems promising, in terms of supporting the narrative.

What happens when we translate this into numbers? Here’s his slugging percentage on balls in play. Again, 2022 on the left.

Again, this looks good! Not a big sample size, but what we have is promising. I’ll take a .938 SLG on top-center pitches. In 2022 his real weaknesses were up and in and middle up. Those zones became strengths in 2023. But he did worse against low pitches. Perhaps this comes from him looking for pitches up in the zone? Maybe it’s just small-sample noise.

What other evidence do we have? The narrative was that in 2022 pitchers feasted on Gorman’s weakness at the top of the zone. Is this true? Did they pitch him up a lot? Let’s look:

Looks pretty similar from year to year, and it looks like they pitched him away more than up. But the narrative held that pitchers always climbed the ladder on Gorman to get a strikeout (his K% was 32.9% in 2022 and 31.9% in 2023). So where did pitchers go when facing Gorman with a two-strike count?

In 2022 Gorman saw a higher percentage of high pitches (in and out of the zone) with a two-strike count than overall (29.3% vs. 24.8%). In 2023 the two-strike/overall difference is negligible (25.5% vs. 24.4%). But, really, in both years the spread looks pretty diffuse, and the two-strike charts don’t look all that different from those showing how pitchers pitched Gorman in every count; they pitched him away. So pitchers don’t seem to have consistently attacked him high in the zone.

Let’s push on. The narrative was that Gorman couldn’t hit high pitches. Could he? Here’s his overall contact percentages:

What about with two strikes against him?

I don’t see any huge differences here, year over year. Let’s look at heat maps for contact!

Again, nothing’s really jumping out at me.

So, what have we learned? First and foremost, we’ve learned that DeebeeDub should leave this kind of work to others. Beyond that, it appears the Spring Training narrative may have overstated the frequency with which pitchers exploited Gorman’s weakness at the top of the zone. But he has indeed become more proficient in whacking balls up high, which supports the narrative, while sacrificing power at the bottom of the zone.

In addition, I’ve learned that relying on quantitative evidence can be overwhelming for a writer. The tough thing is that numbers are true in a way that qualitative evidence (the story) is not, so you can’t just ignore them, but it’s hard to turn numbers into something that most people want to read. This in part explains why even great baseball biographies still lean on old-school statistics like batting average and ERA.

There are so many numbers available that it’s hard to know when to stop digging, opening the door to a near-endless string of charts for your enjoyment. I could break all this into a month-by-month analysis to see whether Gorman improved throughout the season, or look at his performance against different pitch types (does he smash high change-ups but whiff on high fastballs?), or compare him to MLB norms, or otherwise slice and dice the data in a thousand ways. Or I could correct any of the egregious errors I unknowingly committed while interpreting the data.

You know what? I don’t care to do any of those things. I like interesting statistics that deepen my understanding of the game, and I respect people who are comfortable analyzing them. But I can’t control those numbers. I can’t will the pitcher to throw the ball in the precise spot that gives him the optimal chance of success. But I can control the story I tell myself about a game, and a season, and a career. And the story I take from this exercise is that a kid who’s really good at baseball saw a weakness in his game and worked hard to improve it. Yes, I can and should use statistics to support that narrative, but I can also bury myself under so much data that I lose the joy that comes from watching one of my guys crush a high-outside meatball.

If nothing else, my curiosity produced what is probably the shortest DeebeeDub fanpost you’ll ever see. So that’s a plus.

Because I’m a word guy. Who’s numbers curious.

If you'd like to read Fanposts in which I talk about things I actually understand, see:

The Worst of the Worst

The Opening, Opening Day

Phenom...of Flash in the Pan?