The rise and fall of catcher framing

How long can something be new? One of the earliest articles that attempted to quantify the value added by a catcher via framing (authored by Dan Turkenkopf on this very website) is approaching its ninth birthday, but the topic still feels fresh. Framing has been responsible for the biggest shift in valuation among a class of players since Moneyball, and we should enjoy it for a while, even if it's peak is coming to an end.

The sabermetric community is still grappling with how to measure and quantify framing, though the past month has seen a huge improvement on that front. Baseball Prospectus debuted four new statistics on January 12, precisely estimating a catcher's impact on balls and strikes, passed balls and wild pitches, and the running game. Due to the work of Messrs. Judge and Pavlidis, and many others, we are now fairly certain that framing has a much greater impact than the other skills, despite its reduced visibility, and analysts are finally able to quantify the affects --- in this sense, this is the golden age of framing.

However, from another perspective, this might already be the twilight. Framing has been a popular topic for several years, and discussions are no longer confined to the baseball blogs we all love. As acknowledgment of the importance of receiving has become more "mainstream," there are reasons to think it may have actually declined in relevance.

Jeff Sullivan of FanGraphs published a post yesterday noting the reduced year-to-year correlation of framing ability in 2014-15 as compared to earlier seasons and discussed the possibility that umpires are aware of the great framers, and counteract the bias by denying the occasional strike.

Jeff also brought up an alternate explanation, which is that framing is more teachable than hitting, or baserunning, and once teams realized how important it was, they began to emphasize it with all their catchers in the majors and minors, closing the gap between the league's best and worst. To whatever degree either of those theories are correct, it leads to a decline in the importance of framing. Luckily, we now have this brand-new Baseball Prospectus data back to 1988, encompassing the rise in prominence of the skill and, if it exists, the recent downfall.

I came up with a few ways to look at the data. First, and most simply, I looked at the maximum and minimum framing runs per 7,000 chances for each year in the data (1988 through 2015) among players with at least 1,000 chances. These figures are not absolute measures of ability, but ability relative to the rest of the league. If, for example, Andrew Susac was precisely as innately skilled at framing in 2016 as he was in 2015, but the rest of the league was better, his figure would fall. Comparing the best and worst framer therefore illustrates the spread in skill league-wide. If no one is paying attention to framing, or everyone is, the gap should be relatively small, but if a few teams are emphasizing it while everyone else is ignoring it, the gap should be large.

There's a pretty steady maximum and minimum from the earliest year of data through the mid-2000s, at which point the two lines diverge sharply. This corresponds with what we think we know; framing was undervalued or ignored until fairly recently, when a small number teams began to aggressively emphasize it. Since that first jump, however, the gap has been shrinking, and that shrinking has accelerated in the last couple years, indicating a more equal spread of talent.

To add some context, this next chart shows the framing gap, as well as the gap between the maximum and minimum blocking runs per 3,000 opportunities among catchers with at least 500, and the gap between the maximum and minimum throwing runs per 60 stolen base attempts among catchers with at least 10. Each one is scaled to the original gap it had in 1988; figures greater than 1.0 indicate a larger gap, and less than 1.0 a smaller gap.

This chart is nothing but a jumble until the framing spike in 2008, which is remarkable for a number of reasons. First, it's enormous, even if you strip out the 1988 scaling, as framing has the largest run values of any of the three categories. The gap between the best and worst framer of 1988 was 25 runs; in 2008, it was 111. Three digits! The throwing gap barely makes it to two digits in any year, and the blocking gap never gets above seven runs. Framing's 2008 jump can't be dismissed as significant-but-not-meaningful fluctuation.

Second, it's unaccompanied by any of the other measures of the defensive prowess of catchers. This doesn't look like it's the result of a general emphasis on defense, but a specific focus on framing. Third, and most relevant to this article, the trend ever since that leap has been toward greater parity. The 2015 gap was "only" 61 runs, slightly below the 2007 figure and barely above 2001's. This pattern is consistent with a world in which a small number of teams aggressively pursued framers beginning in 2007 or 2008, with an increasing number of other teams catching on each subsequent year. As Jeff said in his article, "if everyone's good, no one is good," and it seems everyone is at least getting better.

The final thing thing I tried to get at was the valuation of framing over the time period covered by the dataset. If teams are paying more attention to framing, we'd expect it to play a bigger role in determining playing time. If good framers have been easier to find in the very recent past, perhaps it's played a diminished role over that period. To get at this, I converted the framing, blocking, and throwing runs to z-scores, and set up a linear regression, with the defensive abilities as independent variables and the change in framing opportunities into the subsequent year as the dependent variable, weighted by the number of framing opportunities in the first year.

When run over the whole sample, all three defensive abilities have a positive coefficient, indicating better defensive skills are correlated with more defensive opportunities in the following year. This is not surprising. Also not entirely surprising is that throwing ability has the largest estimated impact by a substantial margin. A catcher's ability to control the running game is the most visible aspect of his defense, and this data suggests that it has also been the most relevant to coaches, general managers, and other decision makers. That said, framing isn't that far behind, with an estimated impact about 60% of throwing's. Both those coefficients are significant at α = .05, while blocking's estimated impact is much smaller (about 20% of throwing's) and isn't significant.

Those results are for the entire period; what happens when the time frame is narrowed? If the data is restricted to only years after 2007, when the broad adoption of framing began in earnest, the importance flips. Throwing and framing are both still significant at α = .05, and blocking is not, but framing has the largest estimated impact by 50 percent over throwing. This is mostly confirming what we already know – framing matters much more to modern teams than throwing, and much more than it used to – but it's still a sharp and striking change.

Finally, I restricted the time frame even further, to use only the 2014 defensive data to predict the change in opportunities from 2014 to 2015. This gets into sample size issues, for sure, but I wanted to see if things have changed at all in the recent past. Indeed, framing and throwing are again significant, and blocking is not, but throwing is back to leading the estimated impacts by about 65 percent over framing.

One shouldn't overreact to a single year of data, and there are obviously things other than defensive ability that impact changes in playing time. That said, this is another suggestion that the golden age of framing is coming to an end, and that due to reduced scarcity or ability to gain an edge, teams aren't valuing it as they had previously.

One of the most exciting things about the new Baseball Prospectus stats is the ability to do analyses like this (and better) in the future to confirm or debunk articles such as this one. Framing remains, in many ways, the bleeding edge of amateur baseball analysis, and there's tons we still don't know. The professionals, however, might already be done with it, and passing it by in favor of the next big thing.

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Henry Druschel is a Contributor at Beyond the Box Score. You can follow him on Twitter at @henrydruschel.