Review - mvp presentation - do not merge

I've noted this elsewhere but you should store the score components either instead of or in addition to the computed score.

This scoring algorithm looks game-able. By clicking the top answer as quickly as possible I'll probably get one answer right, and do so in such a short time that I'll beat anyone who listens to the tracks. If you'd stored the score components, not just the outputs, you could change this algorithm now and recompute scores for existing games.