  Jittered Sampling is a refinement of the classical Monte Carlo sampling
method. Instead of picking $n$ points randomly from $[0,1]^2$, one partitions
the unit square into $n$ regions of equal measure and then chooses a point
randomly from each partition. Currently, no good rules for how to partition the
space are available. In this paper, we present a solution for the special case
of subdividing the unit square by a decreasing function into two regions so as
to minimize the expected squared $\mathcal{L}_2-$discrepancy. The optimal
partitions are given by a \textit{highly} nonlinear integral equation for which
we determine an approximate solution. In particular, there is a break of
symmetry and the optimal partition is not into two sets of equal measure. We
hope this stimulates further interest in the construction of good partitions.
