fireout

I have new evidence, ie IME, which among othe thins states "at least as likely as not" (equal to or greater than 50%) In her summary and the questionaire that summarizes the the records and exams used ind here evaluation rearding spine injury. The question is where in the CFR 38 do I find the law or regulation that specifies the part where the Veteran is given the benefit of the doubt as in: at least as likely as not (equal to or greater than 50%)? And the other variations of the 50% more or less? I believe I have all the requirements met but i would prefer to quote their own requirennts to leave little remove for interpretation. I have no experience with this DRo stuff so I want to leave nothing to question and will take their SOC apart piece by piece.