I really don't think they give out full marks on the merit of the dance anymore. It's all politics and it's something that is decided by the producers to give some couples more chance or to make the show interesting.
I think series 4 was the last time the judges marked dances fairly. Remember that 40 points for Matt to get Gethin out. As great as Rachel was, did her foxtrot deserve 40 points, especially that early on in the series and don't get me started on Lisa's perfect score. It's all politics folks, don't take it so seriously.
I have to say though Ricky was amazing and I'm glad he is in the final.