A clear-eyed look at Tyler Stephenson’s offense

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The 2023 baseball season is a little more than 40% in the books. And the conventional wisdom told by those (score)books is that Tyler Stephenson is having a disappointing season at the plate. The fall-off from the young catcher’s breakthrough 2022 season has been huge.

But, do the scorebooks tell the full story? Is the conventional wisdom right? Or, is there more to say about Stephenson’s 2023 performance other than nosedive?

2022

Let’s look back a year. Stephenson missed a substantial part of the season due to catching-related injuries. A concussion knocked him out of playing time for two weeks. A broken right thumb cost him a month. Finally, a broken right clavicle (collarbone) on July 23 ended his season. In total, Stephenson played in 50 games in 2022, and all but one out behind the plate. He managed 183 plate appearances.

Stephenson made the most of his time in 2022. He batted .319, which would have ranked third in MLB — right between Freddy Freeman and NL MVP Paul Goldschmidt — if Stephenson had enough at bats to qualify. He hit six homers in those 50 games. Stephenson’s overall power (ISO) was .163. League average ISO was .152.

Dig through last year’s scorebook and you’ll find Stephenson’s composite run production number (wRC+) was a whopping 134 — that’s 34 percent better than the average league hitter. Yowza. 53 catchers had at least 180 plate appearances last year. Among them, Stephenson’s wRC+ ranked third-best.

The front office (and many Reds fans) anointed the 25-year-old Stephenson a cornerstone of the Reds offense.

2023

The good news from this season for Tyler Stephenson is that he’s avoided the IL. Stephenson has already played in 66 of the Reds’ 68 games and had 267 plate appearances. 24 of those games were starts at catcher.

Unfortunately, there’s a load of bad 2023 news about Tyler Stephenson in our scorebooks. He’s batting .249, that’s seventy points lower than last year. His isolated power has plunged from .163 to .105. Add it up and you get a wRC+ of 83 — 17 percent below league average.

Keep in mind, those numbers from 2022 were based on only 50 games and fewer than 200 plate appearances. We already have a lot more data from 2021 and 2023 than that.

Scorebook Outcomes

I’ve made a point of referring to “scorebook” outcomes. The stats we’ve relied on so far — batting average, home runs, power, wRC+ — are based on the official outcomes recorded by the game’s scorer.

For an accurate evaluation of how a player has performed, however, you have to look beyond the scorebook outcomes. They don’t tell anywhere near the entire story.

A batter checks his swing and bloops a ball just over the second baseman’s head — SINGLE in the scorebook. Another batter hits a line drive that the second baseman jumps and catches — OUT in the scorebook. A batter hits a fly ball that lands just between two outfielders — DOUBLE in the scorebook. Another batter hits that same fly ball, but against a slightly faster outfielder — OUT in the scorebook. A batter hits a 350-foot fly ball to left field — HOME RUN in the scorebook because the game is in Great American Ball Park. Another batter hits a 360-foot fly ball to left field — OUT because the game is in PNC Park.

You get the idea. Scorebook outcomes don’t tell much about the quality of contact. For decades, we relied on radio broadcasters to tell us about “screaming line drives” and “bloop singles.” For a few more decades, when more games were broadcast visually, we could see the difference ourselves, but couldn’t measure or keep track of it.

With the advent of ultra-accurate high-tech measurements, we can come up with statistics that allow us to measure and compare quality of contact. And as of 2015, we’ve had the Statcast site to keep track of it.

Stephenson’s True Batting Average

As a reminder, Tyler Stephenson hit .319 in 2022 and is hitting .249 so far this year. Those numbers are batting averages based on scorebook outcomes. The folks at Statcast also look at quality of contact and come up with a stat called “expected batting average” or xBA. It measures what the hitter’s batting average would be assuming typical outcomes of balls put in play. In other words, what is the typical outcome of that soft bloop or that line drive?

Tyler Stephenson’s xBA in 2022 was .260. In 2023 it has been .247.

Good luck with where balls landed relative to the defense helped Stephenson’s batting average by 59 points last year.

We should have known this “adjustment” was coming (did). Stephenson’s BABIP last year was .409. Even if you account for his ability to hit line drives to both fields, which helps a BABIP, there’s no way a slow-footed guy like Stephenson — or any other player — was going to sustain a .409 BABIP. Paul Goldschmidt had the highest BABIP in 2022 at .368. Joey Votto’s career BABIP is .339.

Stephenson’s BABIP is .335 so far this year, almost the same as it was in 2021 (.333). Given how close his BA is to his xBA this year, maybe we should view Stephenson’s .249 batting average as who he is.

Stephenson’s True Power

As a reminder, Stephenson had an isolated power (ISO) of .163 in 2022 and only .105 so far this year. Again, those numbers are based on scorebook outcomes, not actual quality of contact.

Now, let’s look at Stephenson’s xISO (his expected ISO based on contact quality). In 2022, it was .134. This year it is .140. That’s right. Based on the quality of contact he’s made, Stephenson has a higher expected power number this year compared to last. His .163 ISO in 2022 was inflated by luck/defense and his .105 this year has been suppressed by bad luck/defense.

For confirmation, Stephenson’s average exit velocity was 87.1 mph in 2022 and is 87.4 mph this year.

Stephenson’s True Run Production

When you put it all together with a composite, weighted estimate of run production you can use wRC+, which is based on scorebook outcomes or xwOBA which is based on contact quality. Both measures give full credit for walks (more on that in a minute).

As you recall, Stephenson’s wRC+ was that eye-popping 134 last year and sad-face 87 so far this year.

But if you look at Stephenson’s contact quality — how well he has hit the ball — his xwOBA in 2022 was .318. So far in 2023, his xwOBA is .319.

Basically identical.

Full disclosure: Stephenson’s contact rate is down from 76% to 73%. That helps to explain why his true batting average is lower this year. But, Stephenson has boosted his walk rate by 3 points as well, from 6.6% to 9.7%. That latter number is comparable to his walk rate in 2021. His strikeout rate is up a half-percent.

Bottom Line: Who is Tyler Stephenson

Even though his scorebook numbers from last year and this year are radically divergent, the actual difference in performance based on contact quality is small. Stephenson has been a remarkably consistent hitter through the first few years of his career. The ups and downs we perceive are substantially luck driven, not merit-based.

Tyler Stephenson is a league-average hitter. His batting average of around .250 is legit and league average is .248. His power is around .130-140 while league average is around .160. His walk rate is about 10% while the league walks at about 8.5%.

Conclusion

The official scorebook tells one story about Tyler Stephenson. The majority narrative about him is based on it. Broadcasters amplify it. So do most reporters and accounts in social media. That conventional wisdom is that Stephenson’s performance has fallen way off from last year.

So, if you want to be the guy who says “hey, what’s in the scorebook is what he did” and credit those bloop hits more than the line drive outs, that’s your right (and rite) as a baseball fan. But if that’s how you form your opinion about players, you’re apt to be more wrong about the present and certainly the future.

Instead, look at a player’s true performance. You’ll find it in the “x-stats” based on contact quality. True performance is no longer hard to unearth. Every number but one in this post can be found at a single webpage: Stephenson’s player page at FanGraphs.

Here’s what the x-stats say about him: Stephenson’s scorebook numbers last year were inflated from good luck/bad defense by about 30%; while bad luck/good defense is depressing them about 20% this year. Stephenson’s performance has been just about the same this year as last.

That might be disappointing news or encouraging. Tyler Stephenson isn’t going to bat .319 for his career or carry a 134 wRC+. But the 2023 scorebook is due to catch up with Stephenson’s reality soon.

Tyler Stephenson is a league-average hitter; no more, no less. And that’s good for a catcher.

Featured image: Reds Facebook