I recently got a refusal for tier 2 visa because the letter from my bank did not state for how long I have been in possesion of my funds. I agree that this is my fault because I was not paying much attention on the required paper work

I would like to know whether it is possible to be refused a tier 2 visa with no particular reason. What are your experiences? How many times on average do you need to make an application before being granted a visa? I am planning to apply for the second time and I'm now worrying about every little detail since this is my last chance.
Regards, Una