The Big Bang Theory season 4

The fourth season of the American television sitcom The Big Bang Theory aired on CBS from September 23, 2010 to May 19, 2011. Melissa Rauch and Mayim Bialik auditioned and were promoted to the main cast during this season as Dr. Bernadette Rostenkowski and Dr. Amy Farrah Fowler respectively.

Johnny Galecki received a nomination for the Primetime Emmy Award for Outstanding Lead Actor in a Comedy Series at the 63rd Primetime Emmy Awards for the episode "The Benefactor Factor". Jim Parsons won the same award for the episode "The Agreement Dissection".

Production
During the season, Kaley Cuoco's character Penny was absent from episodes 5 and 6 after she fell off a horse and the horse broke her leg. When returning to the series, she was shown working as a bartender instead of waitressing at her usual workplace, The Cheesecake Factory, to hide her injury.

Main cast

 * Johnny Galecki as Dr. Leonard Hofstadter
 * Jim Parsons as Dr. Sheldon Cooper
 * Kaley Cuoco as Penny
 * Simon Helberg as Howard Wolowitz
 * Kunal Nayyar as Dr. Rajesh "Raj" Koothrappali
 * Mayim Bialik as Dr. Amy Farrah Fowler
 * Melissa Rauch as Bernadette Rostenkowski

Special guest cast

 * Steve Wozniak as himself
 * Katee Sackhoff as herself
 * George Takei as himself
 * Neil deGrasse Tyson as himself
 * LeVar Burton as himself
 * Brian Greene as himself

Recurring cast

 * Vernee Watson as Althea
 * Carol Ann Susi as Mrs. Wolowitz
 * Laurie Metcalf as Mary Cooper
 * Kevin Sussman as Stuart Bloom
 * Aarti Mann as Priya Koothrappali
 * Wil Wheaton as himself
 * Brian Thomas Smith as Zack Johnson
 * Joshua Malina as President Siebert
 * Brian George as Dr. V.M. Koothrappali
 * Alice Amter as Mrs. Koothrappali
 * John Ross Bowie as Dr. Barry Kripke

Guest cast

 * Charlotte Newhouse as Joy
 * Annie O'Donnell as Mrs Fowler
 * Eliza Dushku as FBI Agent Angela Page
 * Keith Carradine as Wyatt
 * Rick Fox as Glenn
 * Jessica Walter as Mrs Latham
 * Christopher Douglas Reed as Todd
 * Lanny Joon as Officer Shin
 * Arnold Chun as Ho-Jun
 * Eric André as Joey
 * Tiffany Dupont as Angela
 * Whitney Avalon as Elsie
 * Phil Abrams as Dr Bernstein

Reception
The fourth season received particular praise for character developments. Alan Sepinwall of Uproxx praised the additions of Bernadette and Amy to the cast, writing that "With Amy Farrah Fowler and Bernadette promoted to semi-permanent status, the show is now able to spend large chunks of each episode focusing only on the women, and in the process has made Penny a much more well-rounded character rather than just a foil for the nerds". Emily VanDerWerff of The A.V. Club wrote that "Jim Parsons and Kaley Cuoco's interplay remains the show's secret weapon", and Eric Hochberger of TV Fanatic wrote: "Really though, everything about the main story worked amazing. Mayim fits in perfectly in The Big Bang Theory cast and played off of Kaley Cuoco just as well as Emmy Award-winning Parsons".