In this article we will give an overview of Catchers ERA (CERA) as well as providing a supplement to the work of Chuck Rosciam (who’s work is listed below). With that brief intro let’s get straight to the formula and see if we can explain this new way of measuring a catcher’s defensive prowess.  

THE FORMULA  
CERA= (ER/IP) X 9  

CERA is the acronym for Catchers ERA, or the ERA of the pitching staff of that team when that catcher is behind the dish.  

SOURCES and ISSUES  
What follows is a list of CERA leaders for the past three full seasons taken from the Bill James Handbooks.  

(I) As noted in Mr. Rosciams' article (see link below), these figures are not necessarily the best available. The reason for this is that CERA is calculated in this series of works by taking the total innings caught by a catcher without recording who was pitching during those innings (that is the reason we added the Difference column to our series of charts below. See III for an explanation). In essence what these numbers relate is how an individual catchers ERA compares to the overall team mark regardless of whether or not that catcher caught Tim Hudson and Mark Mulder or Rich Harden and Mark Redman.  

(II) We should also note that the above concern should be extended to include the fact that certain catchers only catch certain hurlers. In the standard example, Eddie Perez was Greg Maddux’s personal catcher for years in Atlanta meaning that his CERA was lower than Javy Lopez because Lopez was never given the chance to catch the pitcher with the league leading ERA figures. Instead, Lopez was “stuck” with Tom Glavine, John Smoltz and whoever else the Braves had (Smiley, Avery, Leibrandt etc.). Therefore CERA shows Perez to be ahead of Lopez artificially, when the truth might not necessarily support that contention.

(III) Another salient factor to point out is that CERA should also be normalized meaning that the teams other catchers ERA should play a part when discussing CERA. For Example Ramon Hernandez catches the wonderful A's pitching staff so of course his CERA will be lower than that of the Tigers Brandon Inge without necessarily meaning that Hernandez is a better catcher. A more indicative total is that of the DIFFERENCE column which show how each catcher performed in relation to the other catchers on his team.   

In the following leaders lists CERA is listed first for all catchers who caught 100 or more games. Following their individual marks in the first three columns, are their teams totals.  

TeamERA w/o C = Team ERA of the “other” catchers on the team

Difference = The amount that the catcher was better than the “other” catchers on his team. A number in (parenthesis) in the difference column is good, meaning the catcher improved his teams ERA by that total.  

 
2003 LEADERS  

Innings Team TeamERA

Caught ER CERA ERA w/o C Difference

2003 Leaders in CERA difference, or the catchers who bested the other backstops on their team by the highest amount: 

1. LoDuca –1.65
2. Kendall –1.44
3. Pierzynski –1.29
4. Mayne -1.07
5. Ausmus –0.99 

2002 LEADERS 

Innings Team TeamERA

 
2002 Leaders in CERA difference, or the catchers who bested the other backstops on their team by the highest amount: 

1. Gil –0.72
2. Kendall -0.63
3. Hernandez –0.63
4. Barrett –0.62
5. Matheny –0.50 

 
2001 LEADERS 

 

** Johnson is the CERA difference leader for a season in the last three years. The numbers:
Johnson- See above. Other Catchers on COL- 324 ER in 369 IP for a 7.90 ERA.  

2001 Leaders in CERA difference, or the catchers who bested the other backstops on their team by the highest amount: 

1. Johnson –3.52
2. Santiago -1.30
3. Ausmus –1.29
4. Miller –1.01
5. Blanco –0.94 

REFERENCES  

Please also read Chuck Rosciam's review of CERA at:  
http://wildpitch.blogspot.com/2004/08/catchers-era-new-defensive-measure.html  

Please also refer to Keith Woolner's article at:
http://baseball-analysis.com/article.php?articleid=432] 

 
RAYS NOTES 
“I have only one superstition. I make sure to touch all the bases I hit a home run.”   - Babe Ruth