  For certain types of quadratic forms lying in the n-th power of the
fundamental ideal, we compute upper bounds and where possible exact values for
the minimal number of general n-fold Pfister forms, that are needed to write
the Witt class of that given form as the sum of the Witt classes of those
n-fold Pfister forms. We restrict ourselves mostly to the case of so called
rigid fields, i.e. fields in which binary anisotropic forms represent at most 2
square classes.
