As a fan of both shows, but a fan of Survivor first, I feel like they're very different games. Big Brother is essentially a game of politics, with the viewers as your voting public. It's about baiting people into conversations that make them look bad to the viewers, about making them commit to attitudes that you know won't be sustainable for 80 days, about crafting a persona for yourself that appeals to the broadest audience while picking holes in everybody else's. Like politics, it's about flinging shit without getting any on yourself. There's a small amount of alliance making I suppose but I don't think it takes you very far, because you don't need numbers. At best it stops you from being a nominee enough that it buys you time to work some magic (and stops you from financially tapping out your fan base too early).
In fact, while I used to think Big Brother was just a popularity contest and Survivor was a better
game show, I've come around to the idea that Big Brother is actually a harder game to play, because there's just so little under your control and so few ways to win. There is no blind sides in Big Brother. If someone is a threat to you (because you suspect they have massive outside support), there's no manoeuvring that can get them out, if they're number one in popularity it doesn't matter who they're up against. All you can do is bait them into controversial arguments to divide their support. Hey Skye, what's your opinion on abortion? She's pro-choice, the anti-abortion part of her fanbase falls away. She's anti-abortion, the pro-choice part of her fanbase falls away. She doesn't go strongly either way, she's a fence-sitter. She avoids the question, she appears weak for dodging the question. She criticises the question for being too serious, she's naive and immature. You're winning no matter the outcome.
One thing I think people underestimate is how much of the game is played in the diary room. It's not like Survivor where confessionals come out when the game is over, the diary room entries are part of the game too, so whatever your plan is, you can't tell Big Brother about it either or else your voters find out too (especially in a game where you have to pretend not to play).
Sorry for my long posts, need an editor