Meaning of Keyword difficulty

[ResourceLab]

Before joining SEOMoz I used to calculate Keyword difficulty with my own method based on keyword density, presence of synonyms, Page rank, title and URL.

This seemed to rather well work and I reach 1st page on a fairly regumar basis by picking good difficulty / interest ratio keywords and only onsite optimization. (No link building)

I just looked @Keyword analysis in SEOMoz. It seems it is only based on page / site autority.

Is this correct? Do you believe keyword and synonym density is irrelevent?

Do I need to set back to my home recipe if I want to include keyword analysis in my difficulty assessment ?

Thx

[ResourceLab]

Thank you Smart Lock

Just to be sure this means I still haev to check Google results individually with SEO_Moz on-page analysis to measure keyword difficulty?

How much time do you devote to keyword analysis on a given topic?

[ResourceLab]

Thanks.

My specific concern is wether or not the SEOmoz Keyword difficulty takes content into account and if not if this is a reliable enough indicator to chose my keywords.

[GoodAtMarketing]

From my understanding the onsite work is only 30% of the pie. To ensure that your onsite is good you can use the SEOmoz on page report card.

If the On page data is good all that's left is who is linking to you, how relevant are they, and how authoratative are they?

The onpage content that you were ranking for may have built natural links. People may have referenced it which helped you get results.