I ask because the creators of the show claimed that you can.
Before the premiere of the Battlestar Galactica episode "Sometimes a Great Notion" (the start of Season 4.5), the Sci-Fi Channel aired a special that recapped the recent events of the series. It went through several plot points, particularly that one of "The Final Five" Cylons was still unaccounted for and that the plot twist from the previous episode, "Revelations", was that:
The crew had found Earth, but it was a lifeless wasteland.
The special in general seemed catered to new viewers. In fact, the creators at one point were on-screen and specifically said that new viewers could definitely jump on at the upcoming episode. They said that Battlestar Galactica was a three-act story and that this was the third act. To further the point, they said that if you've never seen the show before, this was is a great jumping-on point and that it could be thoroughly enjoyed.
Well, I took them up on their challenge (and even watched a re-run of "Revelations"). I knew the gist of the show, I knew what a Cylon was, and I knew the general state of affairs. But I remember being confused by the episode's cliff-hanger: one of the remaining Cylons was…someone who I had never seen before. I'm pretty sure that the recap special didn't mention this person, or if it did, I didn't remember it.
Because I was completely lost at the ending, I decided not to continue with the series. But I'm wondering now: did I have just a bad experience? Is it possible to start watching Battlestar Galactica at Season 4.5 and understand the rest of the series, as the creators claimed? Or were the creators just saying it in an attempt to con new viewers into giving their show a healthy Nielsen rating boost?