piz : )
Thanks to my amazing sponsors: Arcteryx, CAMP-USA, SCARPA, Sterling Ropes, the AAC and WIndX-treme
Here is a way in which you can develop your one arm pull up skills.
Use a towel or rope or sling or whatever and lower your grip on it while your other hand is on a normal jug.
Do reps and lower your hand until you don't need it anymore.
Over a period of a few weeks/months depending on where you are at physically, you will eventually be able to do a one arm pull up.
I don't really do these more than once a month and that might even be a stretch, more like once every two or three months.
There are not really too many routes that require the skill, but having that lock off power is huge when you are trying to boulder or climb at your limit.
As with any type of training, doing too much can injure you and not being properly warmed up will injure you even faster.