While searching for "seo" on Yahoo Search I found out 2 guys that are ranking pretty high , and they are in top #10 ... and they are... I don't known but I don't think that there place should be there It's about Traffic Secrets and Radiate (both comericial websites, offering nothing for free[ no free infos or at a competitive price = less backlinks, no?) So why the rank so high?!
You will need to post the url's to get a specific answer. My initial guess would be the age of the domains, quality and quantity of inbound links and the fact that Yahoo can be manipulated more easily than Google.
Blogs and backlinks seem to dominate Yahoo if you have Title's and Header tags at least they work every other time Post the specific results, it should be easy to answer.
I have found that one really strong backlink will get you to top spots on yahoo, you just have to find the one site that yahoo loves and get a link from it, some of the time pr doesnt matter, I have one page that yahoo loves and I dont mind paying for that link.