A great blues guitarist isn't manifested on how well one can 'shred the axe' but how one can bring they out the soul in their guitar playing.

Keef has exemplified his craft by his renditions of "You Got to Move", "Prodigal Son"
or how he plays own compositions "Sweet Virginia", "High and Dry", "No Expectations", "Love in Vain" and "Dear Doctor". Simple techniques, but he, as I said brings "out the soul".