  We present a numerical method to compute path integrals in effective SU(2)
Yang-Mills theories. The basic idea is to approximate the Yang-Mills path
integral by summing over all gauge field configurations, which can be
represented as a linear superposition of a small number of localized building
blocks. With a suitable choice of building blocks many essential features of
SU(2) Yang-Mills theory can be reproduced, particularly confinement. The
analysis of our results leads to the conclusion that topological charge as well
as extended structures are essential elements of confining gauge field
configurations.
