Moreover, the applicability of the benefit of the doubt doctrine to Mr. Brown's case is a question regarding the applicability of law to the facts of a specific case, which we do not have jurisdiction to review. See Ortiz v. Principi, 274 F.3d 1361, 1365 (Fed. Cir. 2001) ("[I]f the Board is persuaded that the preponderant evidence weighs either for or against the veteran's claim, it necessarily has determined that the evidence is not 'nearly equal' or 'too close to call,' and the benefit of the doubt rule therefore has no application."); Hinton v. Shinseki, No. 2014-7002, 2014 U.S. App. LEXIS 2154, at *9 (Fed. Cir. Feb. 5, 2014) ("[T]o find that the Board erroneously failed to give Mr. Hinton the benefit of the doubt would require us to re-weigh the evidence," which "we lack jurisdiction to address"). Finally, "the sufficiency of a medical opinion is a matter beyond our jurisdictional reach, because the underlying question is one of fact."