I don't like going by h2h. Bookies know that's how squares think. The public places too much emphasis on head 2 head, and not the reasons why that head 2 head record is the way it is. The bookies usually always have the reasons behind the h2h factored in anyway. H2H can reflect an advantage one side has over another, but h2h itself isn't an advantage (unless you're hewitt vs federer).