Ji-Man Choi, Pitch Taker

There’s a left-handed first baseman putting on an absolute clinic at the plate in the World Series. Throw him a ball? He’s not interested. He’ll take and take until you challenge him in the strike zone. Even then, he might take — it’s three strikes to a strikeout, after all, and you might walk him all the same. He’s hitting well enough to keep people honest, but really, the walks are the main event. No, it’s not Max Muncy (or fine, it’s not just Max Muncy). It’s Ji-Man Choi.

Let’s start with the basics. Here are the playoff batters who swing least often at pitches outside the strike zone, minimum 40 opportunities to chase:

Lowest Swing%, Out of Zone Pitches
Player Pitches Swing Rate
Ji-Man Choi 100 11.0%
Austin Barnes 43 11.6%
Robbie Grossman 46 13.0%
Max Muncy 204 13.2%
Marcus Semien 66 13.6%
Austin Nola 49 14.3%
Giancarlo Stanton 73 15.1%
Trent Grisham 54 16.7%
Yandy Díaz 104 17.3%
DJ LeMahieu 67 17.9%

There are plenty of impressive numbers here, because the sample size is tiny. Choi stands above all of them, however. He fares just as well if you break it down into subsets. Here’s swing rate at pitches that aren’t near the strike zone — chase and waste zone pitches, in Baseball Savant parlance:

Lowest Swing%, Chase/Waste Pitches
Player Pitches Swing Rate
Tommy Pham 35 2.9%
Ji-Man Choi 66 3.0%
Yasmani Grandal 24 4.2%
Freddie Freeman 64 4.7%
Tommy La Stella 42 4.8%
Gleyber Torres 58 6.9%
Robbie Grossman 29 6.9%
Max Muncy 139 7.2%
Austin Barnes 27 7.4%
Ramón Laureano 26 7.7%

If you’re curious what swings at pitches in this region look like, here’s one of Choi’s two (two!) such swings this postseason:

It’s not that outrageous of a pitch to swing at. In the playoffs as a whole, batters swing at roughly 17% of those pitches, essentially one in every five. Choi has swung at two out of 66.

His selectivity extends past that. With less than two strikes, swinging at pitches on the fringes of the plate but outside of the strike zone is a good way to get behind in the count. Those pitches a fraction of an inch off the black might get called strikes, but they usually don’t, and they’re generally tough to drive. Choi isn’t quite so passive there, but he’s still been notably good at avoiding them:

Lowest Swing%, <2 Strikes, Shadow
Player Pitches Swing Rate
Brett Gardner 23 8.7%
Giancarlo Stanton 24 12.5%
Max Muncy 65 13.8%
Tommy Pham 21 14.3%
Ji-Man Choi 34 14.7%
Gleyber Torres 20 15.0%
Martín Maldonado 46 15.2%
Willy Adames 65 15.4%
Nick Markakis 32 15.6%
Aaron Hicks 25 16.0%

Why aren’t more people talking about Choi’s batting eye? Partially, it’s because he’s a platoon first baseman on a low-budget team with a breakout playoff star soaking up all the conversations about the Rays offense. Playing next to Randy Arozarena will do that. That’s not the only reason, though. It’s also the fact that Choi has never been this good at it before. Here’s his yearly out-of-zone swing rate:

Out of Zone Swing% by Year
Year Pitches Swing Rate
2016 270 18.5%
2017 46 28.3%
2018 491 20.0%
2019 1067 20.2%
2020 304 22.4%

Those are a portrait of patience, but they aren’t among the very best in the league. Muncy, for example, has posted a lower rate in every year where they’ve both appeared in the majors. On the other hand, some of the reason we don’t hear about Choi as much is because we tend to use bright lines. Not all pitches outside the zone are created equally, which is what Baseball Savant’s Attack Zones attempt to quantify. As a quick refresher, here are those zones:

Pitches in the shadow zone can be in or out of zone, but there are plenty of reasons to swing at those even if they’re on the border. Batters don’t have perfect knowledge of where the ball will end up; they’re merely guessing at probabilities. It’s nearly impossible to tell if a pitch is going to clip the outside corner or end up just off of it, so it’s often right to swing at that pitch even if it ends up outside the zone 50% of the time.

On the other hand, swinging at pitches in the chase and waste zones is clearly bad. Avoiding those swings goes a long way, and Choi has been great at that — roughly equal to oft-cited batting eye deity Muncy and within hailing distance of actual batting eye deity Joey Votto:

Chase/Waste Swing% by Year
Year Choi Muncy Votto
2015 15.0% 8.1%
2016 8.5% 5.8% 9.8%
2017 20.7% 4.4%
2018 8.2% 11.6% 4.2%
2019 8.4% 11.1% 9.4%
2020 9.8% 6.4% 8.9%

That tiny-sample 2017 sticks out like a sore thumb, but aside from that Choi looks to be roughly their equal when it comes to avoiding these pointless swings. The reason he doesn’t stick out like those guys is because he swings more overall; in that 2015-2020 period, Muncy swung 38.2% of the time, Votto 39.8% of the time, and Choi 42.2% of the time.

That contributes to Choi’s lower strikeout and walk rates, at least relative to Muncy. Comparisons to Votto aren’t really fair, because he’s an excellent contact hitter to boot, while Muncy and Choi come up empty more often than league average. It’s hard to say which approach is best, but all three have an excellent ability to work out what pitches they can’t hit and avoid swinging at them.

That’s not to say that Choi’s overall offensive game is as good as Muncy’s. He might have the avoiding bad swings part down, but Muncy does more damage when he connects. He and Choi both hit the ball equally hard, but Choi hits too many grounders; his career 1.21 GB/FB ratio is near league average, while Muncy’s checks in at a minuscule 0.93. That’s why Muncy’s 11.5% barrel rate eclipses Choi’s career 8.5% mark; they both wait for their pitches and both have solid hard hit rates, but Muncy puts more of his in dangerous places.

That aside, is Choi just a less-heralded Muncy? Still no. He’s more limited defensively, despite his ability to do the splits, and more importantly, he’s hitting in situations where he’s best set up to succeed more often. A whopping 86.6% of his plate appearances have come against right-handed pitching, which puts him on the front foot. Nearly every lefty batter sees more righty opposition, but Choi’s mark is extreme even for a lefty. Muncy, for example, checks in at 75.2%. In other words, if Muncy and Choi were both exactly the same hitter, Choi’s numbers would be better — he’s hitting in easier spots.

There’s nothing inherently wrong with hitting in easier spots, but it does limit Choi’s upside, and perhaps makes his true talent worse than we’d expect if we merely looked at his baseball card statistics. At the moment, however, that’s meaningless. The Rays have at most two games left in the season, and the Dodgers will be starting right-handed pitching in both of them.

A Rays victory won’t necessarily involve a Ji-Man walk spree – that’s not how baseball works. His batting eye, however, will be a boon to the Rays in these last two games, an offensive tailwind that could easily be the difference between success and failure — even if no one’s talking about it.





Ben is a contributor to FanGraphs. A lifelong Cardinals fan, he got his start writing for Viva El Birdos. He can be found on Twitter @_Ben_Clemens.

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mikejunt
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mikejunt

I’d be interested to see those postseason charts with a higher PA threshold set (like 80 or 100), as it would do more to show the contrast between Choi and the rest of his team, as well as Muncy and the rest of his. The plate discipline difference is one of the biggest factors in this series, and if I were the Rays I would be very hopeful that this series, win or lose, helps show a bunch of their players the value of improvement in that area.