Ben, I think there's a more appropriate way of looking at Y-DNA test results than in terms of matches. What your Y-DNA test tells you is what genetic markers you have (and don't have) in your Y chromosome, and which other Y-DNA testers have these same markers. If two men share the same markers, they share certain direct male ancestors. They are related, either closely or distantly, depending on which and how many markers are shared. You could say that they're close or distant "matches," but I think the concept of close or distant relatives is more useful. We're all related - it's just a matter of how closely.
There's a huge difference between the results from Y-STR type tests (such as Y-37, Y-67 and Y-111 from FamilyTreeDNA) and a Y-SNP test (such as FTDNA's Big Y). The reason for this is that STRs and SNPs are two very different types of genetic markers, and they provide different information. In my opinion, the most important and useful test (by far) is the SNP-based test. The only real benefit of taking a STR test (again, in my opinion) is to receive, at a relatively low cost, the "predicted" haplogroup it provides (sometimes referred to as a haplotype), which tells you what ancient (thousands of years in the past) genetic grouping you belong to - and, sometimes just as useful, rules out which ancient groups you're NOT connected to. Any of the STR tests provide this predicted group, so you may as well take the cheapest one.
Essentially, SNPs are the mutations in the Y chromosome which have formed over time - a chronological sequence of mutations - and once they're there, they (almost) never change. A SNP test (such as Big Y) measures every genetically useful SNP in your Y chromosome, which allows a direct comparison with every other (Big Y) tester's SNPs. So determining a connection between two Y-DNA testers using a SNP test is really very simple: the longer the sequence of shared SNPs between them, the more closely they are related. Conversely, the shorter the shared sequence, the more distantly related they are, or stated another way, the further back in time their lines branched off from one another.
There are some subtleties in working out exact relationships between relatively closely related men (closer than, say 10th cousins), corresponding to just which cousins would need to be tested, but this is entirely possible through SNP testing.
I hope this answers your question.