These days, Kaley Cuoco is primarily known for playing Penny on “The Big Bang Theory.”

However, viewers who watched sitcoms in the early 2000s probably discovered her through ABC’s “8 Simple Rules,” in which she portrayed Bridget Hennessy, a ditzy high school student who is obsessed with boys, fashion, and popularity.

Also starring John Ritter, Katey Sagal, Amy Davidson, Martin Spanjers, James Garner, and David Spade, the series ran for three seasons before its network lost faith in it, but what led to the show’s cancellation?

As is the case with most great TV shows that get canceled way too soon, “8 Simple Rules” was the victim of dwindling ratings.

Season 1 averaged close to 11 million viewers per episode, while the second installment fell to 9.98 million. That isn’t a massive drop off, mind you, but the third chapter proved to be the sitcom’s death knell, with the show attracting around 6.8 million viewers every week.

By then, ABC executives felt that the series had stayed out of its welcome, and the rest is history.

Despite not being the most popular show on TV during its prime back in season 1, “8 Simple Rules” still boasted a large enough audience to be considered a success for ABC. What’s more, the show might have retained its viewership if Ritter hadn’t passed away at the start of season 2.

While Ritter’s loss was a massive blow to the series, “8 Simple Rules” replaced him with two great comedic actors who brought their charms and sensibilities to the table. However, the show’s creators might have tried to speed through the grieving process too fast, ultimately driving viewers away.

John Ritter, Katey Sagal, Amy Davidson, and Martin Spanjers gave “8 Simple Rules” its heart, as their characters make up the traditional family unit that’s informed successful sitcom formulas for decades.

Losing any of them would have hurt the series, but Ritter—who played the family’s father and husband, Paul Hennessy—was arguably the show’s most important piece.

Most of season 1’s episodes revolve around Paul butting heads with his teenage daughters, Bridget and Kerry (Davidson), while being the ultimate dorky dad.