When I saw The Dark Knight Rises, I was perplexed by the fighting style Batman uses against Bane - specifically, his reliance upon elbow strikes.
I did some research today and discovered that his elbow-heavy tactics are typical of the style of martial arts Nolan chose for the trilogy - Keysi:
This made me wonder how Batman's martial arts repertoire has expanded and changed over time. I remember reading comics in which he used a few well-known martial arts styles:
Keysi
you mentioned is easier to learn and perform, so it was used in the movie. Also, it is a well know fact that Batman uses a mixture of martial arts while fighting Jujitsu, Tae Kwon Do, Judo, Boxing, Muay Thai, Kickboxing, Karate, and Ninjutsu.