How to rate your programming skills [on hold]

How to rate your programming skills [on hold]

I am a student joining graduation course this september. I have been
coding from 4-5 years. I used to think that I was one of the best
programmers in the world. Then I realized I'm not as I participated in
Google Code-In this year. I somehow managed to do 2-3 easy tasks in GCI
after facing so much difficulties.
Many time I try to answer questions at stack overflow but unable to answer
questions except in 2-3 catagories due to hardness of question. I planned
of applying for Google Summer Of Code this year but failed to understood
code base of any organisation. So, I quit.
I have also developed a software within 2-3 months of this year but in VB6.
Now, I have joined oDesk and getting some small coding/fixing jobs.
So, basically the question that comes in my mind is:
Am I a good programmer or a bad programmer?
How can I rate myself in programming in a scale of 1-10?