Why do I see different ranking results for Bing and Yahoo?

[Thos003]

If Bing is running the Yahoo search results then it seems to me the ranks for both Bing and Yahoo should be the same. So why are my SEOmoz ranking reports showing different positions for each?

[KeriMorgret]

Good question Thomas. I'm not sure about this, so I've assigned this question to the help team and will have them come over and give an answer when they have a chance (they normally don't visit Q&A unless an associate or staff member flags a question).

[AlanBleiweiss]

Yahoo actually applies their own criteria to the results.  It's one of the "features" they claimed set them apart from Bing when the deal was consummated.