I will get into the Cubs and Willson Contreras later, but first I must talk about catcher defense in general. One area of the game that is hard for a lot of people to understand or quantify is catcher’s defense. It’s a lot easier to see how a catcher produces offensively than defensively. There are three different attributes which contribute to a catcher’s overall value behind the plate: framing, blocking and throwing. Framing is by far the most important of these attributes. Baseball Prospectus describes framing pitches as “catchers with a knack for good receiving help their pitchers by getting favorable calls from the home plate umpire. This effect has been known ever since umpires started calling balls and strikes. Although it wasn’t always called framing, it has long been a source of speculation and commentary about prominent catchers”. Framing is the most important of the three because it occurs on every pitch so it will have a much bigger impact than something like catcher throwing that might only happen once in an entire game.
There are ways to quantify framing, blocking and throwing in terms of runs. The values are calculated and available on Baseball Prospectus. The model used to calculate framing gives partial credit for each pitch based on that pitch’s likelihood of being called a ball or a strike. A probability map of likely calls is used to determine the likelihood of a ball or strike. Smoothing parameters are added using R to account for the varying strike zones based on counts (3-0 is a bigger strike zone than 0-2). Every variable is taken into account in these models such as batter height difference and hitter handedness. Similar models calculate the amount of runs added from throwing and blocking.
Below is a chart of the top 10 catchers of the 2018 season based on the sum of the three defensive ratings. Every player on this list has had at least 1,400 framing chances this season. You can see the breakdown of where the total value comes from by each attribute. A lot of the guys on this list are guys who not many people have heard of, likely because of their lack of ability offensively. I think it’s interesting to see which guys help their pitchers the most. The ones who stick out to me are the guys that are big names with the bat that have this sort of value defensively. Buster Posey and Yasmani Grandal are the two that stick out to me as some of the best all-around catchers in baseball.
|2||John Ryan Murphy||D-Backs||6.9||0.4||0.1||7.4|
|3||Russell Martin||Blue Jays||4.7||2.4||-0.1||7.0|
|7||Luke Maile||Blue Jays||5.4||0.1||0.0||5.5|
Equally as interesting to me is looking at the worst guys and who is hurting their teams the most behind the plate. A couple of things are intriguing to me here. First, half of this list are from the AL Central, but that division is just awful this year so it’s not a huge surprise. The thing that really sticks out to me is how bad Willson Contreras is at framing pitches. That is clearly the only reason he is on this list. He has good numbers for blocking and throwing, but -9.4 for framing. That is 3 worse than any other catcher on this list of bad defensive catchers! I looked back at last year’s totals and Contreras had a -2.2 for framing last year. That is still bad, but not this bad. He ranked 77th out of 111 catcher last season in total defensive rating.
|95||Omar Narvaez||White Sox||-6.4||-3.6||-0.1||-10.1|
|86||Welington Castillo||White Sox||-4.5||0.0||0.1||-4.4|
The Cubs and Contreras need to figure something out because he is so much worse than everyone else in an area that costs his pitchers runs. Offensively, Contreras is fine, he’s hitting .275 (5th among the 24 catchers with 150 Plate Appearances). He is 10th in slugging, but that’s still not a huge issue and he’s 3rd in WAR. The biggest flaw by far is his pitch framing. Not to call out Tyler Chatwood again, but he walks 8.24 guys per 9 innings. That is awful and 2.5 more than anyone else with at least 50 innings pitched! If you’re pairing him up with Contreras like the Cubs have, this isn’t going to help Chatwood at all. Maybe the Cubs should try using Chris Gimenez to catch Chatwood. Regardless, there is definitely something Contreras does that loses strikes for his pitchers. Whether it’s moving out of his squat too soon to fake a pick off or something he does with his glove, he needs to change something. Hopefully, Contreras changes it up and at least brings himself back to the rest of the bad pitch framers.