“The catching fundamentals are terrible,” said the longtime catcher and manager. "They changed catching, but not for the best," he continued, talking about some of the best catchers of the previous decade.

"Catching today," he added," is a disaster."

If that sounds like it could have been spoken by any number of old-school players and fans talking about the recent transition of many present-day catchers moving to the one-knee-down style of catching, we would agree. But that was Birdie Tebbetts, a four-time All-Star who caught for three teams from 1936-52. He was speaking way back in 1989, to Peter Gammons. He was talking with disdain about legends like Johnny Bench and Carlton Fisk.

Every generation, as it turns out, has opinions on the ones that follow.

If we can agree on anything, it’s that catching today doesn’t really look like it did 10, 30 or 50 years ago. Of course, catching then didn’t look like it did before that, either; backstops in the early days of the sport stood 25 feet behind the batter, with minimal or no protective gear, and caught the ball on a bounce.

As the game and the athletes who play it evolve, so does the strategy that goes into it. “We used to catch underhand, too,” then-Tiger backstop Eric Haase said last year. “Things change.”

So, let’s try to figure out what it actually means when catchers get down into the one-knee stance. It’s understood that it’s meant to help catchers get lower, in order to improve framing, as we’ve learned more about the value of receiving a pitch, particularly on low takes. It’s also popularly assumed that comes at the cost of being worse at blocking.

But is that really true? Since the World Series is going to feature a pair of one-knee catchers in Austin Wells (one knee down 97% of the time) and Will Smith (94%), now seems appropriate to dig into the data and find out.

Wells (82nd percentile) is one of the stronger blockers in the game. Smith (1st percentile) very much is not. What’s behind all that?

* * *

We’re hardly the first to think about this – JJ Cooper at Baseball America in particular has investigated this in depth – but we can try to put some Statcast information to this, since the data tells you exactly where a player’s joints are at pitch release. Based on research from MLB.com’s Tom Tango, the line for a knee being considered “up” or “down” is set at nine inches above the ground, and the rate of how often catchers do that absolutely matches the eye test.

Three years ago, one-knee catching (OKD) and the traditional both knees up were used equally as often, a roughly 50/50 split. That began to change in 2022, continued in 2023, and now, in 2024, we're up to 90% of pitches being received with one or both knees down. Only one in 10 pitches are taken with both knees up in the traditional stance.

At the same time, passed balls and wild pitches -- there’s really no point in splitting them up, because they’re just different human-judged labels on a missed pitch that allows a runner to advance -- have barely budged in years, and are actually down over the last two seasons (that, we think, is at least in part due to PitchCom eliminating some cross-ups).

Put another way, with runners on base, if you look back in four-year spans, there’s fewer passed balls/wild pitches now than in recent years -- even though increasing velocity and decreasing fastball usage and demand to frame pitches and rule changes meant to make basestealing easier makes the job of catcher harder than ever.

• 2012, one PBWP every 164 pitches
• 2016, one PBWP every 146 pitches
• 2020, one PBWP every 143 pitches
• 2024, one PBWP every 183 pitches <<--

One way to think about how overwhelming the setup has become is to realize that only one catcher with any real playing time chose not to use OKD on at least 35% of his pitches this year.

That was San Diego’s Kyle Higashioka, at just 10%, and he A) was originally drafted way back in 2010, and B) explained in 2022 that the reason he doesn’t use OKD is because his “dorsiflexion is way beyond the average,” which is another way of saying that his ankles are so flexible in the right direction that he’s able to get as low as a one-knee catcher without actually needing to get down on the knee. (He’s also been a well below-average blocker the last two seasons.)

Getting low to improve framing pitches is accepted practice at this point, simply because even though a missed frame is far less visible than a passed ball or a stolen base, there are so many more opportunities to do so -- and turning balls into strikes is so valuable -- that overall, it makes sense that it should take priority for a catcher to focus on.

At its simplest, it’s because of what those in the game know. Cubs coach Jerry Weinstein, a long-time college coach and pro catching instructor (who literally wrote the book on catching) noted in 2020 that when looking at pitches that get past the batter to the catcher, “receiving fills up 90+% of the bucket, blocking 6%, & throwing 1%,” in terms of value.

Knowing that, and that the difference between the best and worst framers is approximately 25-30 runs, while the difference between the best and worst blockers and throwers is less than 10, you start to understand why Yankees catching coach Tanner Swanson, considered by many to be the driving force behind OKD in the bigs, told The Athletic in 2022 that “instead of teaching catchers to be receivers from their best block and throw stances, let’s teach them how to be good blockers and throwers out of their best receiving stance.”

Bench, according to the New York Times way back in 1970, also knew the value of getting low, “getting his glove 4 to 6 inches lower than most other catchers in the league — lower even than [Randy] Hundley of the Chicago Cubs,” the same Hundley who popularized the one-handed catching style that Tebbetts so disliked.

Receiving comes first, because it matters most. The called-strike rate -- here we’re showing the rate of how often takes on the edges of the zone become called strikes, which is where most framing value comes from -- in 2024 is easily strongest with a knee down, and weakest with the traditional both knees up stance.

2024 called strike rates, by catcher setup

• Left down, right up // 47.8%
• Both knees down // 46.5%
• Left up, right down // 46.2%
• Both knees up // 45.6%

It’s clear that a knee down, either one, is better for framing than the traditional method. But does doing so make blocking worse? It does not.

Since 2021, with runners on base

• Both knees up // 1 PBWP every 166 pitches
• One knee down // 1 PBWP every 167 pitches

It’s essentially identical. (Interestingly, the biggest differentiator here is which knee is down: left knee down only has a miss only once every 188 pitches, while right knee down only has a miss every 157 pitches.)

It’s that lack of difference -- and other studies have suggested that blocking improves with a knee down -- that answers a popular question, which is generally phrased along the lines of “framing is fine without a runner on base, but why not prioritize that 90 feet when runners are on?” The answer, then: going back to two knees up doesn’t actually help accomplish that.

Some catchers do it anyway, though.

When do both knees go up in 2024?

• No runners on: 7%
• With runners on: 14%

Another way of saying that is that when a knee is down, a runner is on base 41% of the time this year, but in the rare case where both knees are still up, a runner is on base 60% of the time. Whether or not the data supports it, some catchers still do it, in case you were worried about that. The best blocking catcher in 2024, Danny Jansen, is a fan of this style, because when he's both knees up, he's doing it with runners on 70% of the time. When he's using a knee down, he's doing it with a runner on just 4% of the time. There's more than one way to do this.

That Smith (12 blocks below average, one of baseball’s weakest blockers) and Wells (5 blocks above average, one of baseball’s best) both have a knee down more than 90% of the time should tell you something about something. It’s possible to be an excellent blocker with a knee down. It’s possible to be poor at it, too.

Austin Wells

Wells, a rookie, was the third-best framer in baseball this year, per Statcast data. He was an excellent blocker as well, with his +5 blocks saved above average putting him in the 82nd percentile, showing that it is possible to be good at both skills with a knee down. His backup, 2022 Platinum Glove winner Jose Trevino, is even better at both skills (88th percentile or better in each), and defers playing time primarily due to a much weaker bat and throwing arm. He, too, is on one knee 95% of the time.

Wells has been excellent, also, in the postseason, adding two blocks above average, and in some tremendously big spots to save his pitchers:

That’s not to say he was perfect -- he did let two balls get by him. The first came on a steal attempt as he was getting to his feet on a low pitch. The second was a little less understandable: He took a slider off the face, which is a bad play no matter where your feet are. Of course, that has little to do with positioning, and we’ve seen that kind of miss in big spots with traditional setups, too.

Wells is a good example of a catcher who changed his setup, going from right knee down 84% of the time last year to just 27% of the time this year, moving to a more-dominant left knee down setup.

Since Wells rarely ever catches with both knees up, we can’t give you a 1:1 comparison between the styles for him, other than to say that he suffered a wild pitch or passed ball once every 205 pitches with runners on base this year, far better than the average.

Will Smith

On the other side, Smith has had a much different -- and far more confusing -- defensive path. Over the previous three seasons, Smith rated as a plus blocker (+11 blocks saved, a top-20 mark), an average framer (-3 framing runs), and an average-ish thrower (0 throwing runs, though the inability of the Dodgers pitching staff to hold runners last year made it look worse).

This year? He’s been rated the best throwing catcher in the game, while also being the weakest framer and a bottom-5 blocker, while also using the one-knee down setup more than ever, up to 94% from 82% last year.

It’s difficult to explain, really. Smith spoke in May about a focus being on stopping basestealers, and the team did allow 27 fewer steals this year. But if the OKD setup were to blame for the weakened blocking, it shouldn’t also have hurt his framing, too -- particularly on the bottom edge, where he collapsed from a 56% called strike rate last year to a 47% rate this year. It’s likely there’s something more going on here, and perhaps it is as simple as trying to catch more stealers at the expense of everything else. Either way, he was a more valuable defender in 2023.

Smith’s confusing year aside, it’s clear that catching with a knee down makes for better framing and -- at worst -- doesn’t hurt blocking. (It’s good to remember that some of the most egregious looking misses come on pitches that also would have been hard to block with knees up.)

But don’t just take the data’s word for it. Listen to those who have actually done it.

Sal Fasano, an 11-year Major League catcher and most recently Atlanta’s catching coach, summed it up concisely when speaking to The Athletic in September.

“If blocking was at zero when I played, blocking is at, like, plus-20 now,” Fasano said. “In the old days, when we had two knees up, it was really hard to get your knees down at the same time. That’s why being on one knee is actually easier. If both knees hit (the ground) off-time, it stiffens your body. Think about it: if you jump and land one foot at a time, your body’s actually going to vibrate, your eyes are going to vibrate, it’s chaos for your body. On one knee, it’s a slide, so you’re calmer. You can absorb the ball better, you can do a lot of things.”

That’s the part -- the wear and tear on the catcher -- that gets a little lost, because it’s so hard to quantify. Back in 2012, Sandy Alomar Jr., who caught two decades in the bigs and at the time had undergone 10 knee surgeries, laughed to the New York Times that “I feel lucky I can still walk,” which tracks with a recent study that suggested a catcher’s knees absorb up to seven times more pressure when in a squatting position.

It’s a thought echoed by three-time All-Star Jason Varitek, who in 2021 noted it could have helped his career; and three-time All-Star Willson Contreras, who said in 2022 that it takes some of the stress off a catcher's back; and two-time All-Star and current Cleveland manager Steven Vogt, who said this year that catchers are “going to be able to play a lot longer. They’re not going to take the pounding and the wear and tear in their knees and hips and back like a lot of the traditional catchers did.”

"I feel more comfortable behind the plate," J.T. Realmuto said back in 2021. "In a traditional stance for me, I'm not as comfortable as I am with one knee down." That's basically what Twins catcher Ryan Jeffers, a former Swanson student, told the Score last year. "For me, it's a lot easier to block that way," said Jeffers. "You can make your blocking decisions a lot later, whether you need to block, or not, because you are already near the ground."

If the men wearing the gear keep talking about how much they prefer it, maybe we should listen to them -- or remember that Tony Pena Sr. and Manny Sanguillen were catching with one or both knees down decades ago.

Patrick Bailey, considered the sport’s preeminent defensive catcher, is down 95% of the time on a knee. Austin Hedges, a non-factor at the plate who gets to start ALCS games because of his defense, is down 99% of the time. All six catching Gold Glove finalists, as it turns out, were down on a knee at least 94% of the time. The days of pretending that just because it doesn’t look like it used to means that it can’t be effective are over.