I've done pretty well at Kaggle with just a Bachelors in American History: http://www.kaggle.com/users/19518/vik-paruchuri, although I haven't been using it as much lately. A lot of competition winners have lacked advanced degrees. What I like most about Kaggle is that the only thing that matters is what you can show. I learned a lot, and I highly recommend it to anyone starting out in machine learning. I expanded on some of this stuff in a Quora answer if you are interested: http://www.quora.com/Kaggle/Does-everyone-have-the-ability-t....