One-Knee-Down Catching Has Taken Over The Majors

Image credit: Sean Murphy (Photo by David J. Griffin/Icon Sportswire via Getty Images)

When the first iPhone was released in 2007, it was notable for how different it was. That year and for a year or so afterwards, you noticed when you saw someone using one, as it was a dramatically different phone from all the candy bar, flip phones and Blackberrys that were the norm.

But within just a few years, the slab-style/touch-screen type iPhones and Android copies had become ubiquitous. Before long, anyone carrying a flip phone seemed to be a relic from a different time because consumers quickly decided that a slab phone with a touchscreen was way better and more useful than a flip phone.

In Major League Baseball, one-knee-down catching has reached an iPhone level of pervasiveness with conventional setups going the way of the flip phone.

When Baseball America first studied this in 2021 with a look at regular catchers from the 2020 season, we found 41% of MLB catchers used a conventional setup, 39% used a one-knee-down (OKD) setup and 20% used a hybrid approach, varying between the two. There was an almost 50-50 split between the two approaches.

When we looked again using the regular MLB catchers from the 2022 season, we found that 56% used the one-knee setup, 36% used a traditional setup and 8% used a hybrid setup. The one-knee setup seemed to be gaining an upper hand.

Updating this with the results from the 2023 season, the one-knee takeover has become the clearly dominant form of catching in the majors. Last season, 68% of catchers used a one-knee setup with runners on base, 21% used a conventional setup and 12% used a hybrid approach, flipping between conventional setups and one-knee.

If anything, this may undersell the steady growth of one-knee-down catching in the majors. The vast majority of the MLB catchers who still use a conventional setup with runners on base regularly use a one-knee-down setup with no one on base. Austin Barnes and Kyle Higashioka were the only two of the 68 catchers who didn’t regularly use a one-knee setup at all. I can’t promise they didn’t use it as well without watching thousands of pitches, but in a spot check of multiple games, they were using the conventional setup with no one on base.

What does this mean? In the major leagues, the benefits of the one-knee setup is now seen as a settled debate. Fans may argue about it, but coaches and players in the majors have accepted it to near universal adoption.

One-knee-down setups have not been found to cause issues with blocking in the majors. The passed ball/wild pitch rate has dropped in recent years as one-knee catching has become more pervasive. Individually, seven of the top 10 catchers in Baseball Savant’s blocking ranking are OKD catchers and two were hybrids. Adley Rutschman, who ranked 10th, was the only catcher who used a conventional setup with runners on base who ranked in the top 10.

It has not been found to hinder a catcher’s ability to throw—the top six and eight of the top nine in Baseball Savant’s caught stealing above-average use OKD, and all of the top 10 in average pop time use OKD.

And when it comes to framing pitches, the advantages are significant. Only two of the top 20 catchers in Framing Runs Above Average (FRAA) use a conventional setup. Seven of the bottom 11 in FRAA use a conventional setup with runners on base, and another two use a hybrid setup. There were only 14 conventional setup catchers in the study (and one didn’t qualify for the FRAA leaderboard), so more than half of the conventional setup catchers were among the worst framers in the majors.

The problem with a traditional setup is it makes it tougher for catchers to frame the low pitch. Of the 13 qualifying catchers who used a traditional setup, Higashioka is the only one who didn’t have at least one quadrant at the bottom of the zone where they framed at a below-average rate.

Viewed a different way, while there are many fans and even some ex–big leaguers who view one-knee catching as a massive detriment to defense and catching in general, to believe that, one has to accept that all 30 MLB teams have decided to adopt an approach that’s detrimental to winning.

Believing that one or two MLB teams have adopted a misguided strategy seems possible, but believing that all 30 teams have independently come to a misguided conclusion that has led them to all adopt an inferior approach is hard to explain.

The way we studied this to classify catchers has remained relatively consistent over the three different years we’ve studied, although the arrival of the Baseball Savant Catcher Blocking leaderboard has made the work much easier. For every semi-regular MLB catcher (68 catchers qualified in 2023), we look at five different blocks (or attempted blocks) with runners on base. We make sure to look at balls that bounced well in front of the plate, others that were to the left and right of the plate and a couple of high and away balls to see if a catcher varies his setup in different situations.

If for all five block attempts a catcher uses the same setup, he is classified as either a conventional or one-knee-down (OKD) catcher. If there is any variance, another five block attempts are viewed. If two or more of the 10 block attempts are from a different setup than the others, he’s classified as a hybrid approach. If only one attempt of the 10 shows a different setup, another five block attempts are viewed. If after those 15 attempts are viewed, two or more are in a different setup, the catcher is classified as a hybrid setup. If only one of the 15 is from a different setup, the lone differing setup is thrown out and he is classified for his dominant setup.

If anyone wants to replicate or confirm my classifications, you can easily do so by simply going to the Baseball Savant Catcher Blocks leaderboard, click on any catcher’s visuals and then toggle on the pitches to click pitches to view. All the rankings are taken from the extremely useful Baseball Savant leaderboards.

Player	Team	Setup	Blocking Rank	Framing Rank	Caught Stealing Rank
Murphy, Sean	ATL	OKD	1	5	11
Kirk, Alejandro	TOR	OKD	2	13	40
Fortes, Nick	MIA	Hybrid	3	21	50
Realmuto, J.T.	PHI	OKD	4	62	17
Moreno, Gabriel	AZ	OKD	5	36	1
Diaz, Yainer	HOU	Hybrid	6	52	13
Hedges, Austin	TEX	OKD	7	2	30
Rogers, Jake	DET	OKD	8	14	35
Zavala, Seby	AZ	OKD	9	15	49
Rutschman, Adley	BAL	Conventional	10	12	23
Contreras, William	MIL	OKD	11	6	41
Stallings, Jacob	MIA	Conventional	12	53	44
Trevino, Jose	NYY	OKD	13	10	34
Gomes, Yan	CHC	Hybrid	14	44	22
Vázquez, Christian	MIN	OKD	15	20	25
Thaiss, Matt	LAA	OKD	16	38	24
Maldonado, Martín	HOU	Conventional	17	63	19
Smith, Will	LAD	OKD	18	39	36
Lee, Korey	CWS	OKD	19	N/A	37
Casali, Curt	CIN	Conventional	20	N/A	N/A
Gallagher, Cam	CLE	OKD	21	11	21
Adams, Riley	WSH	Conventional	22	54	33
Kelly, Carson	DET	Hybrid	23	37	15
Jansen, Danny	TOR	Conventional	24	24	47
McGuire, Reese	BOS	OKD	25	29	39
Díaz, Elias	COL	Conventional	26	58	7
Grandal, Yasmani	CWS	Hybrid	27	17	62
Nola, Austin	SD	OKD	28	46	53
O’Hoppe, Logan	LAA	Conventional	29	56	52
Maile, Luke	CIN	Conventional	30	40	20
Fermin, Freddy	KC	OKD	31	31	12
Naylor, Bo	CLE	OKD	32	22	46
Alvarez, Francisco	NYM	OKD	33	4	54
Herrera, Jose	AZ	OKD	34	49	N/A
Heim, Jonah	TEX	OKD	35	3	8
Knizner, Andrew	STL	OKD	36	50	42
Narváez, Omar	NYM	OKD	37	28	48
Stubbs, Garrett	PHI	OKD	38	N/A	28
Perez, Salvador	KC	OKD	39	57	45
Contreras, Willson	STL	Hybrid	40	55	10
Sánchez, Gary	SD	OKD	41	25	16
d’Arnaud, Travis	ATL	OKD	42	18	59
Barnhart, Tucker	CHC	OKD	43	19	43
Mejía, Francisco	TB	OKD	44	51	26
Campusano, Luis	SD	OKD	45	42	N/A
Rodríguez, Endy	PIT	OKD	46	35	14
Amaya, Miguel	CHC	Hybrid	47	26	38
Barnes, Austin	LAD	Conventional	48	27	60
Delay, Jason	PIT	OKD	49	16	57
Caratini, Victor	MIL	OKD	50	8	56
Stephenson, Tyler	CIN	Conventional	51	60	51
Wynns, Austin	COL	OKD	52	23	4
Murphy, Tom	SEA	Conventional	53	45	55
Pérez, Carlos	OAK	Hybrid	54	N/A	N/A
Jeffers, Ryan	MIN	OKD	55	48	61
Haase, Eric	CLE	OKD	56	43	32
Raleigh, Cal	SEA	OKD	57	9	9
McCann, James	BAL	OKD	58	34	18
Pinto, René	TB	OKD	59	N/A	N/A
Wong, Connor	BOS	OKD	60	47	6
Wallach, Chad	LAA	OKD	61	33	31
Bailey, Patrick	SF	OKD	62	1	2
Ruiz, Keibert	WSH	Conventional	63	61	63
Bethancourt, Christian	TB	OKD	64	41	5
Zunino, Mike	CLE	OKD	65	30	29
Langeliers, Shea	OAK	OKD	66	59	3
Higashioka, Kyle	NYY	Conventional	67	7	58
Sabol, Blake	SF	OKD	68	32	27