(comment redacted! – I can't repeat the results today. Perhaps I was missing a Solr commit ... since the index is behaving differently, and I didn't change the index, though I did restart Solr a few times.)
(below left for historical purposes)
I may have stumbled into something. Try setting q.op explicitly.
gives me a lot more results than
oddly, q.op=OR gives me the same results as setting it to AND.
Why did I stumble into this?
"In Solr 1.4 and prior, you should basically set mm=0 if you want the equivilent of q.op=OR, and mm=100% if you want the equivilent of q.op=AND. In 3.x and trunk the default value of mm is dictated by the q.op param (q.op=AND => mm=100%; q.op=OR => mm=0%). Keep in mind the default operator is effected by your schema.xml <solrQueryParser defaultOperator="xxx"/> entry. In older versions of Solr the default value is 100% (all clauses must match)"
I have q.op set in my schema, thus:
<solrQueryParser defaultOperator="AND" />
but when I use the q.op parameter, I experience something different. Wild!
Does this give us any insights?