What is the mapping between them? Timus has a lot of problems rated < 200, but they also have problems rated above 10,000. The problems also seem more chaotic. I've done some of the first problems, and even the easiest require some tricky thought, but then if I scroll down to more hard problems, some of those are easy.
Does there exist some statistics for comparing timus and cf problems? Or do anyone whos used both sites have an opinion?