In reply to Offwidth:
Everything starts with a 10/10 and loses points for things that warrant the loss of points.
Also factored in is a "what was it AIMING for?" consideration.
Thus, something like Brooklyn's Finest which was never angling for serious instant classic status or playing for Oscar nominations, gets a high score (8/10 or maybe 8.5/10) because it does little wrong. Yes it's a b-movie. Yes, it may be forgotten after a year, and never be some enduring classic like, I dunno, Inherit the Wind.
On the other hand, The Shawshank Redemption which has "serious movie" written all over it, is both full of clunkers AND fails to deliver on its promise, so it gets a lower score (probably still 7.5/10, not sure as I have not accurately reviewed it under this system).
i.e. I factor in "what did you EXPECT". Otherwise great animated films like Zootropolis would lose out every time to heavyweight dramas. It's the "What Hi Fi"magazine method, to ensure that their review of a £200 component is fair when reviewed against a £23k component.
Yet I have to be consistent. So Until the End of the World, although I love it, is admittedly a jumbled mess with indulgent diversions, poor comic relief, a total lack of chemistry between romantic leads, a lumbering and disjointed pace etc. ANd that is when I'd need to evangelise or at least write something down beyond just the score.
My favourite film, Once Upon A Time in the West, gets 7.5/10.
I've seen film magazines do similar, e.g. a 3 star score but a glowing review with the odd caveat.
Post edited at 14:42