Here’s a video briefly explaining the progression to achieve chest-to-bar pull ups. Although elusive, this movement stresses a large amount of your musculature, allowing you to burn more calories and increase strength.

I also mentioned the butterfly technique in this video. I would highly suggest working on the butterfly technique separate from your C2Bs until you are proficient in both movements. The butterfly style, although more efficient, tends to be more stressful on the body, especially the shoulder joints. Practicing the kipping style C2B first will allow you to build the strength and stability needed in the butterfly motion.

Hope this helps!

P.S. Again, sorry for the narrow screen!