Assessing beer quality

I've been thinking. Dangerous, I know. Thinking about the Whitbread Gravity Book. And how to convert the subjective assessment of beer quality into something more manageable. A number.

It occupied my thoughts as I sat on the sneltram this morning. How to convert those descriptive terms into a simple number. Eventually, I had an idea. A simple one, as mine usually are. I don't have the brain for complexity. Anyway, here's my idea. I'll give each of the descriptions a number. Zero is the level of just acceptable. Here's a slightly more graphic representation:

+3 v good
+2 v fine
+1 fine
0 moderate
-1 poor
-2 v poor, going off
-3 nasty, sour, foul, gone off

I'll be able to work out average scores for each beer type from a brewery and for a brewery overall. Any score below zero will be an indication of poor quality. Simple, eh?

Yesterday evening I quickly scanned the Gravity Book entries for a couple of breweries. I'm pretty sure I spotted a couple of patterns. But let me get some real numbers together before I spin any hypotheses.