Lets Play a Little Keyword Game

So I'm doing some keyword research and this one scares me a bit. Lots of high ranking pages with lots of links, but only partial match to my keyword or none at all.

So heres the stats. My keyword is 3 words we'll label them A B C in that order.




1st page - big company, has word A and B in title. (subpage)
2nd page - Again word A and B (home page)
3rd - same (subpage)
4th -Includes A B and C word in the correct order in both (subpage)
5th - No keyword match at all that I can see in the URL or Title
6th - no match in the url, A and B match the title
7th - A and B match in title and URL (sub page)
8th - Same as 7 but homepage
9th - A, B and C match in both the URL and Title (homepage) this is a Niche site/sniper site
10th - A and B for both URL and Title (subpage)

(subpage) = means its a subpage thats ranking
and I think that makes it pretty obvious what (homepage) means

The other little twist is that about half of the time these sites are using the plural version of keyword B vs singular for my longtail keyword.

How does plural vs singular versions of the same word play into rankings?

This search gets about 1600 local searches a month and CPC is approx $9.50