|Click to enlarge.|
After finishing a review, I ask myself, "What fraction of my audience will enjoy this?" (I neatly sidestep divide-by-zero issues thanks to the visitor counter not being able to distinguish my own pageviews). I round to the nearest of the above five percentages and that's where the score comes from.
This should be perfectly compatible with most other scoring schemes people use. I have explained why and what my rationale is elsewhere.
I may decide to bias a score for political or personal reasons. I intend to fully disclose the nature and extent of this bias when it happens. Most likely, the bias will consist of a +1 to the initial score.
Something you should keep in mind: The review and the score may appear to disagree. This shouldn't happen, but it probably will. As far as judging whether you'll like the thing in question, go with what the review says. Say you read a review for a movie which, to you, sounds scathing and you were sure I'd give it a 2, but I gave it a 4. You probably shouldn't watch it.
For video games, I have a habit of saying "don't bother playing it, but watch a Let's Play". If I'm saying that, the score is for playing the game yourself. The score is also a measure of whether you will like the game or not. If the game is fun for 2 hours but boring for the remaining 8 of the single-player campaign, I may state this, give it a good score, and expect that you will stop playing once the fun part is over. Length is irrelevant, so don't count on me giving low score for short games and high scores for long games.