The ratio of the measured B → D(*) l nu decay rates for tau and lighter leptons deviate from the Standard Model (SM) by about 4 standard deviation. I will discuss why the data is in tension with SM predictions, independent of complications in modeling exclusive decays, and complementary measurements that can be made to reduce associated theory uncertainties. I will then classify how new physics might be responsible for the central values, with a focus on minimizing the amount of ad hoc flavor assumptions. Several explicit scenarios, including previously unidentified ones with connections to other outstanding flavor anomalies, are possible, with experimental signatures observable in the future at ATLAS/CMS, LHCb, or Belle II.