There's nothing that gets my dander up more than hearing gastroenterologists spout statistics about how many ERCP's you have to do before you are prepared to do a sphincterotomy. I traced the origin of that number and found a "study" where a gastroenterologist, with no training in ERCP, decided to seek such training. He used 100 cases as a goal, and after performing these cases in training, he started doing ES. His results were good. Based on this, he recommended that everybody should do 100 ERCPs. You call that a study? And it is often quoted.
I did about 10 ERCP's in my endoscopy fellowship with Jeff, and had to go to a small rural hospital to do my sphincterotomies, because my main hospital wouldn't let me do them (why should anybody be allowed to do an ERCP if they aren't allowed to do the sphincterotomy). Of course the main hospital eventually relented and granted my privileges.
I am sorry to say that I do less than 10 cases a year, yet I still feel very comfortable doing the procedure, and my results are very good. Although I admit that I am occasionally unable to cannulate, I have had no complications at all. Most of my cases are for CBD stones, and I can easily avoid over injecting the pancreatic duct (I have a good radiologist who can tell me what duct I am in before I even inject contrast).
I think that the bottom line is that everybody is different, and some of us can do something a few times and be good at it, and others can do it 1000 times and never get it right. We just have to figure out which category we fit into.