9 — Best of Genre. This is an album that represents one of the best recordings of a particular genre, or a historically important recording/album. It is something that every listener interested in the genre and its history should hear. It is a rating that is used sparingly — not every artist has a 9.

8 — Best of Artist. These represent the best albums the individual artist has to offer. These are landmark albums within their own catalog that every fan should hear.

6 — Good. While these records aren’t as fine as ones that are rated “Best of Artist,” they still are quite strong, and offer a fair number of worthwhile songs.

4 — OK. These records are generally failed experiments, bland genre exercises, botched compilations, records filled with uneven material — anything that doesn’t quite fit the artist’s normal quality standards. For dedicated fans, there are songs of interest, but other listeners shouldn’t bother.

1 — Poor. The poor rating is reserved for albums that are out-right disasters or rip-off collections. The poor rating is used almost as sparingly as the Best of Genre rating — in other words, it should only be used when an album is a complete waste of money, such as a collection or re-recordings that bills itself as a “Greatest Hits” compilation.

As i recall, I would submit a numeric rating which was then converted to stars. With acts with extensive catalogs, there definitely does seem to be a case of too many cooks in the kitchen.

BAIFP: I get it, but as I look at the Winwood discography page, I’m not sure the stars provide any useful info. “Arc of a Diver” and “Back in the High Life” each get four and a half, but there’s no indication within the review as to why; “About Time,” which includes some lukewarm comments from the reviewer, gets 3 and a half, which is just a tick less than “Nine Lives,” which is worshipfully reviewed and given four. As you suggest, regarding the star system, the Allmusic FAQ says “we only compare a release to other releases by the same artist.” Reading the reviews alone without the stars would not give a reader the idea that “Diver” or “High Life” are superior to “Nine Lives.” So there’s a disconnect there, at the very least.