This Article untangles the effects of the Supreme Court\u27s latest word on the Erie doctrine, by taking the vantage point of a lower court trying to uncover the logical implications of the Court\u27s new pronouncement. First, Shady Grove lightly confirms the limited role of constitutional constraints. Second, it sheds only a little light on judicial choice-of-law methodology. Third, by contrast, it does considerably clarify the conflict between Federal Rules and state law: if a Rule regulates procedure, then it is valid and applicable without exception in all federal cases, to the extent of its coverage; in determining the Rule\u27s coverage, federal courts should, when alternative readings are defensible, read it to minimize its intrusion on substantive rights (that is, they should construe a Rule in a fashion that includes considering the impact on the generalized congressional and state interests in regulating substance, but they should not adopt a narrowed construction just to avoid conflict with the state\u27s interests peculiarly in play in the particular situation presented by the case at bar). In the end, Shady Grove has not fundamentally altered Erie, but it mercifully makes the current interpretation more comprehensible