Sara's winning chances have increased due to the fact she has solely inherited the "old teams" (Jen, Luke, Dale, Rebecca, Dennis, Mario, Lisa) support, Rachel has yet to find any as they still remain in the house.
Once Kat, Micheal and Rex (in particular) have fallen you watch that balance of a mere 2-3 % points claw back into Rachel's favour.
Yeah just a slight lead now with so much of an inherritted fan base, I woulnt even waste a cat nap worrying about it