is war underrating catchers?

[filihok]

I am not taking about the defense effect on ERA, but the catcher's effect on (defense independent) pitching WAR.

Ok.
That doesn't negate that every player who dons a glove for a team has an effect on that team's pitchers' ERAs.

If you can find a way to quantify the catcher's effect on pitchers' performance you'll be a hero in stat nerd world.

[filihok]

I quickly plotted the numbers for 2012

WARGraph.jpg

This is using FanGraphs' numbers

A couple of things to remember:
FanGraphs' replacement level is about 43 wins
FanGraphs' pitcher war is based on FIP not runs allowed
for a single season, one should expect more error as wins and losses will compound as one team beats another

The model still matches real life observations very well:
The expected intercept is at 43. The observed intercept is at 44.9
The expected slope is 1. The observed slope is .958

[filihok]

Just did 2011 and 2010

2011
WAR2.jpg


2010
WAR3.jpg

[filihok]

Then, I randomly selected 30 teams.

I did this by using the Random Integer Generator at Random.org

I got the following numbers

Random1.jpg

Random2.jpg

Random3.jpg



I used these numbers to select the teams.

The first group of numbers was for 2012
The second group of numbers was for 2011
The third group of numbers was for 2010

So, for example, the first random number was 26. This was the 26th team in the 2012 set which was the Colorado Rockies with 30 WAR and 64 wins. I continued like this for each group.

Unfortunately, I found the random number generator sometimes produced the same number within a run. When this happened I skipped that number and moved onto the next team, leaving that slot temporarily blank. I then ran the generator for a forth time and got the following numbers

Random4.jpg

I used these to fill in the blanks. Using the first two numbers to fill in the missing slots in 2012, the second two for 2011 and the third two for 2010.


That gave me this data set.

WARCORR.jpg


So, for the sample set the equation is: y=1.0367+40.731 with an R2 of .71972
compared to an expected equation of: y=1+43


Not as exact as the data from the article, but, still enough to show that WAR is measuring what it claims to measure.



*probably could have done this much more smoothly...but...it's late...and once I started I didn't want to start over.

[brett]

Thanks for all the work.

[dominik]

Regarding the influence of catchers on ERA: I know this is almost impossible to quantify because there is no catching rotation and sometime the backup catches always the same pitcher so the numbers are likely skewed but does anyone know what the leagues ERA numbers of of games caught by starting catchers vs backups are. Is there a difference at all ( well the backup is not always worse- some teams have a good catcher that cannot hit at backup but it might give an idea overall )?

[drstrangelove]

Catchers, because of the demands of the position, typically do not produce as much as other players.

It's as simple as that.

Where do catchers rank all time in things like runs, hits, doubles, triples, home runs, rbi, games, plate appearances, etc? Are catchers not treated 'fairly' by those stats?

If you want to make WAR a rate stat (to normalize for playing time) you can take all players' WAR and divide by PA's. Then multiply by 500 or 600 or 700 or whatever. I imagine that you'll find that catchers' WAR per whatever number of PA's compares to that of other positions. Just as their H/PA, 2B/PA, 3B/PA, HR/PA, RBI/PA etc would.

http://www.baseball-reference.com/ab...position.shtml You mean this, I reckon?

under Rpos, Positional Adjustment Runs

[filihok]

http://www.baseball-reference.com/ab...position.shtml You mean this, I reckon?

under Rpos, Positional Adjustment Runs

No.

I mean if you divide the above stats by the number of PA's and compare them they will be similar

In 2012 per 700 PA's
Catchers: 155 hits, 31 doubles, 1 triple, 21 home runs, 60 walks, 139 K's
Non-Catchers: 161 hits, 31 doubles, 4 triples, 19 home runs, 55 walks, 138 K's
*per baseball-reference

Unfortunately, I can't easily do this for WAR

According to FanGraphs (which doesn't fully separate out stats for by position. For example, all of Mike Napoli's stats are included under both catcher, first base and DH since he played all those positions) catchers provided 3.0 WAR per 700 PA's compared to 2.5 WAR for the rest of the league.

Again, no evidence that catchers are shortchanged by WAR