I'm trying to get a few files that are apparently fairly rare. They're part of a larger set other members of which are more common. There is a search query, call it "X", that matches them all and narrower queries, call them "X Y" and "X Z" for example, that match specific individual ones.
Here is the strange thing. The broad "X" query finds everything, including occasionally the rarer files in the set. All of the less rare get found in numerous copies and downloaded easily; all of the rare ones get found occasionally with sources in ones and twos and a couple of these have also eventually downloaded.
But the narrower "X Y" searches, though each matches the name of one of the rarer files found by the "X" query, never seem to generate any search results (other than spam)!
What would cause this phenomenon? It seems that the narrower search should if anything be more effective, and certainly not less -- a rare file whose name matches the "X Y" search should be found by both searches whenever both are run and a source for it is online. There's no reason for it to ever be found by the "X' search while never being found by the "X Y" search, given the assumption that all its sources don't intentionally and systematically withhold results that match narrow queries they receive, while responding honestly to broad ones. (And that seems to be a pretty safe assumption -- who in their right mind would program a p2p client to do so, and how would every single source for a particular file end up happening to use such a client when such clients are expected to be super-rare if they exist at all? Assuming Shareaza 2.5.3.0 is not such a client, as seems extremely probable, it's no longer true for the two of the rarer files that I have thus far succeeded in downloading, in particular. Surely others have downloaded one of the other files that don't have a client that behaves in such a manner, then.)