Forget about your Rats and Snakes. This is the correct Survivor zoology. It is your final 4 nealy every time.
The Fox: Sets themselves up as the person to beat.
The Bear: The "Loyal Opposition." A strong opponent chosen by the Fox because of their loyalty.
The Goat: A person who cannot win who is selected as an easy beat by the Fox and the Bear. The Goat's loyalty is insured by a guarantee of 2nd or 3rd place.
The Bunny: A person selected because of their weakness to lose at the F4. The Bunny is also selected because of their general pleasantness.
Though the Bear will probably beat the Fox in a vote, the Fox cannot attack the Bear until the end game. The game, thus, becomes a fight between the Fox and the Bear for immunity, for jury votes and for the loyalty of the other end game players.
S2 provides the most obvious example of this:
Fox = Colby, Bear = Tina, Goat = Keith, Bunny = Liz.
Once the merger vote happened, Colby Tina and Keith were three of the final four. The only question was who was going to be the Bunny, Amber, Rodger or Keith. I imagine Liz was chosen because Amber was partisan to Colby and Rodger perceived as partisan to Tina and Keith.
S1 Fox = Rich, Bear = Rudy, Goat = Sue, Bunny = Kelly.
In S1 a glitch occured. Kelly, by back scheming proved herself unworthy as a Bunny. Her challenge wins brought her into the end game against the will of the alliance. They decided on a new Bunny, Colleen (then Sean, then they were stuck with Kelly).
Definition: a bad Bunny = a RAT.
Normal Fox/Bear/Goat/Bunny play goes as follows:
F4 Bunny voted out.
F3 Fox and Bear fight it out. Winner takes the Goat. (The Fox and Bear should have been duking it out for the loyalty of the Goat all along.)
Winner of F3 or Goat's choice wins.
We all know Colby's choice of Tina was a tactical mistake. Obviously Rich's choice of Kelly was a tactical mistake
Even in alliances, you can see the makings of Fox/Bear/Goat/Bunny.
Jerri's Kids Fox = Jerri, Bear = Colby, Mitchell = Goat, Amber = Bunny. (Jerri should have seen that this alliance was doomed. She couldn't win a vote against any of them!)
Kuchas Fox = Michael, Bear = Rodger, Goat = Liz, Bunny = ? (Alicia given a fair shot despite her strength, Nick?, Tina or Amber?)
But there was a Kucha Counter alliance Fox = Jeff, Bear = Alicia, Goat = Nick.)
Obviously the key to a succesful alliance is to find a Goat. Being a Fox makes you vulnerable as you are going to be held responsible for most of the conniving and backstabbing. You need to either find someone you can beat or establish that you are clearly dominating the game and deserve to win by your skills. A good Fox will pit enemies against each other and can justify votes as removing the weak, unworthy and traitors. The best Fox will be seen as just and fair. Such a player is a LION.
The Lion is the most succesful strategy, a leader that commands loyalty and respect. Potentially, Michael could have beaten all the other players in a vote, even Rodger.
The trouble with the Lion strategy is that early on someone too strong is seen as too clear a winner, thus a threat. A good Lion must build loyalty first, then establish leadership. And leadership does not mean telling everyone what to do. It means being the person that other people turn to to make decisions.
Being a good Bear is the next best strategy but the Fox selects the Bear and usually chooses a weaker player. (The F3 challenge in mind.)