I think it could even be done by voting. Not voting for problems, but voting for the best solutions and explanations in the comments. Handpicking best problem

I think it could even be done by voting. Not voting for problems, but voting for the best solutions and explanations in the comments. Handpicking best problem and writing detailed explanations could be quite hard for one person, but if a lot of people find someones explanation useful and insightful, and vote for it, then one person could handpick from roster of problems with good explanations. That would also help platform by engaging visitors to not only learn math, but to teach the parts they know well to others. (I also found out that explaining math to others really helps you to understand it better, so win|win)