A former CBS executive reveals that The Big Bang Theory was only greenlit after Kaley Cuoco was cast as Penny. Bill Prady and Chuck Lorre's nerdy sitcom may be one of the most successful shows of all time, but it almost didn't happen. After the original The Big Bang Theory pilot was shown to the network, they were asked to rework it due to some storytelling issues. Amid everything that Prady and Lorre changed in it, swapping its main female character was apparently their most significant move.
In a new interview with Emmy Magazine (via The Direct), former CBS executive Nina Tassler recalls the issues they had with the unaired The Big Bang Theory pilot. They also recognized the potential in the idea, so instead of scrapping it, they asked Lorre and Prady to change some of its elements. This resulted in Amanda Walsh's Katie being changed to Cuoco's Penny. Read her full quote below:
"There was so much about the pilot that did work. But there were parts of the script that didn't work, and we had to recast an actress. [Chuck Lorre] is such an extraordinary talent. He had a great concept and wonderful chemistry between the two leads, so I asked him if he would try again. And he immediately said, to his credit, 'You're right, I know I can do better. Thank you for this opportunity, and we'll figure it out.' Sure enough, he did. Kaley Cuoco joined the cast, and she was the secret sauce. Chuck and Bill Prady delivered a pilot script, and the rest is history."
While Walsh was great in the role of Katie, she didn't work in terms of The Big Bang Theory's storytelling. Katie was too hardened and worldly and it pitted her against Leonard and Sheldon. Penny, on the other hand, was kind from the get-go. It doesn't mean, however, that she could be pushed around. In fact, she was the very first character in The Big Bang Theory who called out Sheldon for his bad behavior.
Penny perfectly toed the line between being understanding and assertive. She never let Leonard and the rest of the cast disrespect her. Penny functioned as the audience's point of view in the sitcom, and she was effective in that role. It's also clear that she had a positive impact on the more socially-awkward members of the Pasadena gang.
Most importantly, however, the inclusion of Penny was arguably the only reason why Sheldon worked as a character. As great as Leonard was, he was too passive to call out his roommate for being unreasonable, which only fueled his sense of entitlement. Penny's arrival in The Big Bang Theory kickstarted Sheldon's personal growth. Without her, his antics would have hampered the show overall.
