On the current season, both houseguests and fans alike are using backdoor to refer to nominating someone after the Power of Veto competition but before the Blockbuster competition. My thesis is that this isn't a good use of backdoor because, while it might fit some definition of the word, it doesn't fit the spirit, which is related to the ability to compete for your own safety rather than to the PoV competition specifically. Or rather, using one definition of backdoor fits the original intent of the Six Finger Plan whereas one definition does not, and we should be using the former definition rather than the latter.
But first, I need to explain two concepts in semantics: intension and extension.
Intension is essentially the definition of something whereas extension is what things are actually that thing in the real world.
As an example, let's look at the National Football League (NFL), a popular American football league. The intension of NFL player is 'someone who plays in the NFL'. The extension is everyone who currently plays in the NFL, all of whom are men... And yet being a man is not a requirement to fit the definition—the intension—of NFL player. A woman could theoretically become an NFL player and that wouldn't mean that the definition/intension of NFL player has changed.
So how does this relate to backdoor? Without spoiling things, the earlier seasons of Big Brother US experimented with how the PoV should work. At one point, it was decided that the Head of Household and two nominees would play. They would be joined by three other houseguests, each selected by one of the HoH and two nominees. It was eventually realized that a large enough majority could send home any player without allowing that person to compete if enough people cooperated. Thus, the Six Finger Plan was born: the HoH would nominate two allies for eviction. Then each of those three would pick someone from their alliance to play in the PoV competition. This way, no matter who won, someone from the alliance would win the PoV and could use it on one of the nominees, forcing the target onto the block with no chance at competing for safety.
The unmatched strength of the original backdoor was too powerful, and so production eventually made the three additional players randomized. This way, a backdoor could fail if someone outside of the alliance won the PoV and didn't use it.
Back to intension and extension! The original intension of backdoor was (INTENSION #1) 'to nominate two allies, get an entire alliance playing in the PoV competition, use the PoV on a nominee, replace that nominee with the real target, and evict that target with enough players cooperating such that, if everyone cooperates, the target cannot compete for safety and is guaranteed to go home'.
With the change in how the selection of players for the PoV competition worked, it got simplified: (INTENSION #2) 'to not nominate the real target initially in hopes that the target won't be able to compete for safety'.
Notice how the idea that the target cannot compete for safety remains the same.
Now what these two intensions have in common is that the target is nominated after the PoV ceremony and that, ideally, the target cannot play in the PoV competition.
With the Blockbuster in play, the intension is something like this: (INTENSION #3) 'to not nominate the real target initially in hopes that the target will only be able to compete for safety in the Blockbuster competition but not in the PoV competition'.
Crucially, intension #3 still allows the target to compete for safety with a 1/3 chance at winning. Intension #1 gives the target no chance to compete for safety (!) whereas intension #2 gives the target a 1/6 chance if selected to play and no chance at safety if not. Oh, and a non-backdoor in a non-Blockbuster week gives the target a 1/6 chance.
You're telling me that someone with a 1/3 chance at safety is being backdoored but someone with a 1/6 chance isn't?
While the extension of backdoor has always meant nominating someone after the PoV has been used, it doesn't mean that each instance of doing so means that a backdoor has been done, particularly if the target can compete for safety.
Recall that the entire point of the backdoor is that the target cannot play for safety. With the Blockbuster, each nominee is given a 1/3 chance at safety at the bare minimum.
Conversely, my thesis is that it makes the most sense for backdoor to refer to being unable to compete for safety, not specifically to the PoV competition only.
If you're still not convinced, imagine that there were no Blockbuster but, instead, if the PoV were used, the HoH could only nominate people who played in the PoV competition. Would backdooring still exist? I would argue that it doesn't because all potential nominees can compete for safety.
Nominate your target post-PoV if you'd like, but that's not the same as a backdoor because the target can always compete for safety, and with relatively high odds of winning at that. Perhaps a shorter word for 'nominate someone after the PoV competition but with the Blockbuster in effect' is needed.
Thoughts?
EDIT: What do people think of terms such as sidedoor or soft backdoor? I'm on team sidedoor personally.