In these lectures I discuss the impact of soft hadronic physics on
predictions for B decays. Unfortunately our tools for calculating these effects
are limited; even after the use of the best available tools the resulting
theoretical uncertainties are difficult to delimit, and can obscure tests for
the presence of beyond-Standard-Model physics. The first lecture reviews what
tools are available, the second reviews in more detail two examples of how
these tools can be used.Comment: Lectures presented at the XXVII SLAC Summer Institute on Particle
Physics, July 7-16, 199