I was just reading some recent blogs, and out of interest I saw ratings of OptimusPrime090, the graph took a wild spike in the last contest (#727), and when I explored more into his recent contests, I found that he had got a rank of 1k by solving 0 problems!!! (whereas I got 2417 in the same).
Is this a bug or something else I'm confusing with, as it looks very strange to me!