Big Brother always tries to shake things up in their season premieres, but some connect with fans more than others, as evidenced by their IMDb rankings. Every season premiere has a similar structure where they tease what lies ahead in the upcoming months but also have some sort of exciting event, like a competition or an early eviction. These first episodes are so important because they introduce the cast members as well as new and exciting twists for that season.

https://screenrant.com/big-brother-season-premieres-ranked-by-imdb/