Robert_Charlton - 8:28 am on Dec 11, 2010 (gmt 0)

On the bad end of this, I did a very specific search: n*wb*rn be*ly b*utt*on inf*ction which turns up no relevant results for me, but it used to turn up exact matches that were very helpful before oct 22nd.

Whatever it turned up, I don't think it was exact matches. Searching on both Google and Bing, quoted and unquoted, I see that Google returns 9 exact matches for the phrase, one of which is this WebmasterWorld thread. Bing returns 13 exact matches, but several of the urls returned are the same with different query strings.

Possibly, the confusion might be that for the unquoted search, both Bing and Google return in the #1 position a discovermagazine.com article which does not contain an exact match for the noted query. Bing returns the article whether the query is quoted or unquoted, but Google returns the article only when the query is unquoted.

Regarding how Google says it treats exact matches, this might be a useful reference....

Google query modification - the official word
http://www.webmasterworld.com/google/4212716.htm [webmasterworld.com]

Google does officially use synonyms. I've also seen Google not return an exact phrase match (one that I know exists) for a quoted search but return the same phrase for an unquoted search.

Titles are held to a higher standard, and an exact match title won't return a page that Google feels has other problems (like dupe content).