  This chapter explores how we might use the observed {\em statistics} of blue
stragglers in globular clusters to shed light on their formation. This means we
will touch on topics also discussed elsewhere in this book, such as the
discovery and implications of bimodal radial distributions and the "double
sequences" of blue stragglers that have recently been found in some clusters.
However, we will focus particularly on the search for a "smoking gun"
correlation between the number of blue stragglers in a given globular cluster
and a physical cluster parameter that would point towards a particular
formation channel. As we shall see, there is little evidence for an intrinsic
correlation between blue straggler numbers and stellar collision rates, even in
dense cluster cores. On the other hand, there is a clear correlation between
blue straggler numbers and the total (core) mass of the cluster. This would
seem to point towards a formation channel involving binaries, rather than
dynamical encounters. However, the correlation between blue straggler numbers
and actual binary numbers - which relies on recently determined empirical
binary fractions - is actually weaker than that with core mass. We explain how
this surprising result may be reconciled with a binary formation channel if
binary fractions depend almost uniquely on core mass. If this is actually the
case, it would have significant implications for globular cluster dynamics more
generally.
