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Hello good people. Quick question about the Keyword Difficulty Tool (which is great by the way).  I am wondering specifically about the "keyword difficulty score" If I were to type in "blue widget,"  the tool returns a diffiiculty score of 51%. "red widget" on the other had returns a score of 40%. My question is how much more difficult is the term, "blue widget" when compared to "red widget?" 20% harder? more, less? I just don't know.  I'm sure the info is somewhere on the seomoz site, but I have searched high and low and cannot find it. Thanks a lot, Joe