New/Updated Metric on Catcher Defense from BP

[Nate Colbert]

Interesting read (I thought) over at Crawfish Boxes about BP's new/updated defensive catching metric which integrates presentation (read: framing), throwing and blocking into a single number and indicates where Max Stassi and some of the Astros minor league catchers rank.

Summary: Stassi and Tyler Heineman good. Roberto Pena (surprisingly*), Alfredo Gonzalez not so good.

*or perhaps not as his particular skillset (arm) is considered much less important than framing in the overall impact on saving runs.

Explanation and table at BP.com here and here. The Crawfish article also notes possible biases/limitations in the data.

Major league catchers are also included in the table and Castro comes off well. The Congerbot showed a significant dropoff from 2014 to 2015 with his throwing problems obviously part of the decline but his framing numbers were a bigger issue.

[jbm]

Conger mysteriously lost his magic?  More likely, the magic was never there at all.  Catcher defense isn't nearly as mysterious as sabre people want everyone to believe.

When there is a high variability in a measure that by all accounts should be relatively stable, one should look hard at the measurement rather than who is being measured. 

[moriartp]

When there is a high variability in a measure that by all accounts should be relatively stable, one should look hard at the measurement rather than who is being measured.

I believe that is precisely what BP is doing here.

[jbm]

I believe that is precisely what BP is doing here.

Yes, I think you are correct.  I was referring more to the CB article where they were trying to explain Conger's "dropoff" by "injury, inattentiveness, or something else entirely."  My feeling is that there is nothing to explain: whatever skill Conger had in that regard is most likely the same now as it was  in 2014.

[VirtualBob]

Yes, I think you are correct.  I was referring more to the CB article where they were trying to explain Conger's "dropoff" by "injury, inattentiveness, or something else entirely."  My feeling is that there is nothing to explain: whatever skill Conger had in that regard is most likely the same now as it was  in 2014.

I wonder if there is a Heisenberg Principle in the background here. The more we talk about certain guys "framing" skills conning the umpires, the more the umpires adjust by correcting for the con.  Our attempts to measure the phenomenon may be impacting it.

[Navin R Johnson]

Conger had to have some sort of injury to lead to such a dropoff in throwing out runners.

[Duman]

I wonder if there is a Heisenberg Principle in the background here. The more we talk about certain guys "framing" skills conning the umpires, the more the umpires adjust by correcting for the con.  Our attempts to measure the phenomenon may be impacting it.

I also wonder if they account for number of times a certain ump calls your game.  If you are a backup who is lucky enough to have wide zone ump behind the plate, it can skew your sample size.  Just one more variable that can impact this stat.

[VirtualBob]

I also wonder if they account for number of times a certain ump calls your game.  If you are a backup who is lucky enough to have wide zone ump behind the plate, it can skew your sample size.  Just one more variable that can impact this stat.

Right.  And that wide-zone ump might account for a large fraction of the supposedly adequate sample size.  The pitches are not independent in the ordinary statistical sense.