Here is their formula: https://www.criticker.com/explain/ I've rated 600 movies after some weeks there (first 100 movies in a first day, next 100 in the next week, etc) Now I think it's precise, it does begin to work after 10 or 100 rated movies. It's not good at recommedning new movies, but it is good at predicting whether I will hate a movie or not, thus it doesn't recommend me trash that I hate, which makes it better than Netflix.