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Salvador Perez and pitch framing

A still somewhat controversial concept, but pitch framing is probably a real thing. And Perez seems to be getting better at it.

Hannah Foslien

In a season of whiningmisery, an utter lack of offense, and questionable roster management, it's been difficult to find a somewhat bright spot. Even our own fellow writers aren't that bright. Nevertheless, for my first article here, I will attempt to bring some optimism. It'll probably end up more like putting a band-aid on something that needs surgery, but you're here and I'm here, so here we go together.

Anyway, Salvador Perez. He's the man. He's a solid offensive catcher with a generally elite defensive reputation. So often has that elite defensive reputation been on display when he throws out dirty thieves attempting to steal OUR bases. However, there is another aspect of catcher "defense" that has gained traction in recent years: pitch framing. Here's our own Jeff Zimmerman writing about pitch framing using catcher author Jason Kendall and Brayan Pena as examples.

If you want a quick refresher, or you haven't heard of it before, pitch framing is the idea that a catcher has the ability to influence the call of a ball or strike based on how he receives the pitch. To be sure, it's a messy concept. For example, how do you separate the effect of the pitcher on pitch framing? Cliff Lee is more likely to get a strike call on the edge than Carlos Marmol, I would surmise.

Due to the PITCHf/x system, we can quantify this ability now, and the numbers have good correlation year-to-year, which suggests that the numbers are measuring a real phenomenon. While the numbers probably aren't exactly accurate, it's fairly established that this is a real thing. Whether it should be a real thing is a different story. It's here, and until we have terminators cameras calling balls and strikes, it's probably here to stay.

It's taken a long time to get to this point, but it's time to show you some numbers. From Matthew Carruth's StatCorner website, here are Perez' framing numbers from 2011 to now.

Year Sample zBall% oStr% Calls PerGame RAA
2011 3158 17.4% 5.2% -66 -1.64 -8.8
2012 5636 17.0% 5.8% -97 -1.34 -12.9
2013 9541 14.5% 6.6% -46 -0.38 -6.2
2014 3360 12.1% 7.0% -2 -0.05 -0.3

zBall% represents the percentage of pitches caught within the strike zone that are called a ball. oStr% represents the percentage of pitches caught outside the strike zone that are called a strike. There is a clear trend here; Perez is getting fewer balls called within the strike zone and more strikes called outside the strike zone. Looking at RAA, the runs above average where 0 is average, Perez is about an average framer now instead of a poor one.

How about some other numbers? Exact quantification of this skill is still an inexact science, so more numbers are better in my opinion. Baseball Prospectus also keeps track of framing numbers. Here are their numbers from 2011 to now.

Year Framing Chances Predicted Strikes Actual Strikes Extra Strikes Framing Runs Added By Count Framing Runs Added By Call
2011 1832 793.7 747 -46.7 -5.9 -7.1
2012 4463 1873.9 1811 -62.9 -7.7 -9.4
2013 7231 3141.8 3119 -22.8 -3.4 -3.4
2014 3390 1186 1127 -59 0.6 -8.8

There is a somewhat similar trend, at least from 2012-2013. Focusing on the framing runs added with context (i.e., the count) taken into consideration, Perez has become about average at framing. Focusing on the extra strikes number, Perez has actually declined as a framer. However, that number depends on how much stock you put into Baseball Prospectus' model that produces the predicted strikes number. The trend is more important than the absolute number. Let's not get caught up in gory math.

So, what do we make of these numbers? I am sure some of you will disagree with these numbers. Some of you will certainly disagree with the concept in general. That's OK. There is a rulebook strike zone, and it should be followed. Umpires are human, though. I'm not confident in saying that Perez has become a good or even average framer. These are two data sources that have some disagreements with both the sample size and the value Perez has produced from framing. Given that the 2014 season is still young, I'm not sure how much stock should be put into the 2014 numbers just yet, but he is approaching the 2012 sample size.

Despite these limitations, I'm fairly confident in saying that Perez has improved as a framer. If Perez is better at offense, defense, calling games, and framing pitches than the other mitts on the bench, it makes sense why Yost won't let him ride the pine. At least somebody is improving at something.