Dozens of law review authors and judges have proclaimed a Chevron Revolution in the Supreme Court's willingness to defer to agency interpretations, but few authors have examined this claim in a systematic empirical manner. Seeking a more factually grounded understanding, Professor William N. Eskridge, Jr. and Lauren Baer, Esq., conducted an empirical study of all 1014 Supreme Court cases between Chevron (1983) and Hamdan (2006) in which an agency interpretation of a statute was at issue. Eskridge and Baer conclude that there has not been a Chevron revolution, at the Supreme Court level anyway. The new deference regime associated with the Chevron decision continues to exist alongside older deference regimes, including Skidmore, Seminole Rock, Beth Israel, and Curtiss-Wright. Indeed, from the time it was handed down until the end of the 2005 term, Chevron was applied in only 8.3 percent of Supreme Court cases evaluating agency statutory interpretations. Instead, the Court has employed a continuum of deference regimes. This continuum is more complicated than the literature or the Court's own opinions suggest, and it is a continuum in which Chevron plays a modest, perhaps even minor, role. Perhaps the authors' most striking finding is that in the majority of cases - 53.6 percent of them - the Court does not apply any deference regime at all. Instead it relies on ad hoc judicial reasoning of the sort that typifies the Court's methodology in regular statutory interpretation cases. Eskridge and Baer find that neither Chevron nor the other deference regimes is applied consistently by the Supreme Court. The authors find some functional regularities, however. The Court is most likely to defer to agency interpretations when they are consistent with norms recognized by the Justices, reflect the application of genuine expertise to a statutory problem, and are pursuant to delegated lawmaking authority. Eskridge and Baer also find that almost all of the Justices vote ideologically; that is, conservative Justices are significantly more likely to agree with conservative agency interpretations, and liberal Justices are significantly more likely to agree with liberal ones. The last portion of the article applies the empirical findings to address normative questions. Based upon an examination of constitutional structure and legitimacy; the rule of law and the regnant super-statute, the APA; and institutional competence, Eskridge and Baer argue against proposals that either significantly expand or jettison the special Chevron two-step framework. The authors' main prescriptions are friendly amendments to the Court's practice and recommendations that judges rethink basic doctrines of statutory interpretation in light of the modern administrative state.