To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
Show all languages
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.

From Wikipedia, the free encyclopedia

Catcher's ERA (CERA) in baseball statistics is the earned run average of the pitchers pitching when the catcher in question is catching. Its primary purpose is to measure a catcher's game-calling, rather than his effect on the opposing team's running game.[1] Craig Wright first described the concept of CERA in his 1989 book The Diamond Appraised.[2] With it, Wright developed a method of determining a catcher's effect on a team's pitching staff by comparing pitchers' performance when playing with different catchers.[2]

Baseball Prospectus writer Keith Woolner has written that "catcher game-calling isn't a statistically significant skill" after doing statistical analysis of catcher performance.[2] Sabermetrician Bill James also performed research into CERA, finding that while it is possible that catchers may have a significant effect on a pitching staff, there is too much yearly variation in CERA for it to be a reliable indicator of ability.[1] James used simulations of catchers with assigned defensive values to directly compare CERAs, which influenced Woolner to perform similar simulations but instead using weighted events to calculate pitchers' runs per plate appearance.[1] Through this, Woolner concluded that even if catchers do have an effect on pitchers' abilities to prevent runs, it is undetectable and thus has no practical usage.[1] He also stated that "the hypothesis most consistent with the available facts appears to be that catchers do not have a significant effect on pitcher performance".[1]

YouTube Encyclopedic

  • 1/3
    23 007
    12 215
    145 877
  • The Most INSANE Baseball Team In The WORLD
  • The Top 10 Catchers from the Divisional Era
  • Buster Posey Career Highlights (Giants all-time great catcher retires)



  1. ^ a b c d e Woolner, Keith (2002-05-29). "Aim For The Head: Simulating Catcher's ERA". Baseball Prospectus. Retrieved 2007-06-20.
  2. ^ a b c Woolner, Keith (2000-01-10). "Field General or Backstop? - Evaluating the catcher's influence on pitcher performance". Baseball Prospectus. Retrieved 2007-06-20.

See also

This page was last edited on 1 August 2022, at 22:17
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.