  This paper compares the results of two SBBN codes developped independently by
different teams of physicists. These two codes have significant differences
that lead to a discrepency between their final mass fractions of Helium-4 of
0.003. This paper shows that the mass fractions of each code had different
orders of convergence, and how the number of timesteps affects the accuracy of
the mass fractions. At the end, the paper shows how to modify both codes so
that their Helium-4 mass fractions agree to around 0.0001.
