The B factories at SLAC and KEK are producing tens of millions of bottom (b) quarks per year, allowing us to probe the structure of quark flavour-changing transitions with unprecedented precision. It is hoped that such precision studies will shed light on the nature of the nature of the vacuum and the origins of mass. However, in order to interpret the experimental data, theoretical predictions with the same level of precision are required, despite the fact that the confining nature of the strong interactions makes b quark decays tremendously complex. In this talk I will discuss the long-standing problem of making precision theoretical predictions in strongly-interacting systems, and discuss some of the progress that has been made over the past decade or so using effective field theories and the heavy quark expansion to study b quark decays. Finally, I will discuss some recent developments in the field.