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.

PlayerTeamSetupBlocking RankFraming RankCaught Stealing
Murphy, SeanATLOKD1511
Kirk, AlejandroTOROKD21340
Fortes, NickMIAHybrid32150
Realmuto, J.T.PHIOKD46217
Moreno, GabrielAZOKD5361
Diaz, YainerHOUHybrid65213
Hedges, AustinTEXOKD7230
Rogers, JakeDETOKD81435
Zavala, SebyAZOKD91549
Rutschman, AdleyBALConventional101223
Contreras, WilliamMILOKD11641
Stallings, JacobMIAConventional125344
Trevino, JoseNYYOKD131034
Gomes, YanCHCHybrid144422
Vázquez, ChristianMINOKD152025
Thaiss, MattLAAOKD163824
Maldonado, MartínHOUConventional176319
Smith, WillLADOKD183936
Lee, KoreyCWSOKD19N/A37
Casali, CurtCINConventional20N/AN/A
Gallagher, CamCLEOKD211121
Adams, RileyWSHConventional225433
Kelly, CarsonDETHybrid233715
Jansen, DannyTORConventional242447
McGuire, ReeseBOSOKD252939
Díaz, EliasCOLConventional26587
Grandal, YasmaniCWSHybrid271762
Nola, AustinSDOKD284653
O’Hoppe, LoganLAAConventional295652
Maile, LukeCINConventional304020
Fermin, FreddyKCOKD313112
Naylor, BoCLEOKD322246
Alvarez, FranciscoNYMOKD33454
Herrera, JoseAZOKD3449N/A
Heim, JonahTEXOKD3538
Knizner, AndrewSTLOKD365042
Narváez, OmarNYMOKD372848
Stubbs, GarrettPHIOKD38N/A28
Perez, SalvadorKCOKD395745
Contreras, WillsonSTLHybrid405510
Sánchez, GarySDOKD412516
d’Arnaud, TravisATLOKD421859
Barnhart, TuckerCHCOKD431943
Mejía, FranciscoTBOKD445126
Campusano, LuisSDOKD4542N/A
Rodríguez, EndyPITOKD463514
Amaya, MiguelCHCHybrid472638
Barnes, AustinLADConventional482760
Delay, JasonPITOKD491657
Caratini, VictorMILOKD50856
Stephenson, TylerCINConventional516051
Wynns, AustinCOLOKD52234
Murphy, TomSEAConventional534555
Pérez, CarlosOAKHybrid54N/AN/A
Jeffers, RyanMINOKD554861
Haase, EricCLEOKD564332
Raleigh, CalSEAOKD5799
McCann, JamesBALOKD583418
Pinto, RenéTBOKD59N/AN/A
Wong, ConnorBOSOKD60476
Wallach, ChadLAAOKD613331
Bailey, PatrickSFOKD6212
Ruiz, KeibertWSHConventional636163
Bethancourt, ChristianTBOKD64415
Zunino, MikeCLEOKD653029
Langeliers, SheaOAKOKD66593
Higashioka, KyleNYYConventional67758
Sabol, BlakeSFOKD683227

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