  The use of rapidity gaps is proposed as a measure of the spatial pattern of
an event. When the event multiplicity is low, the gaps between neighboring
particles carry far more information about an event than multiplicity spikes,
which may occur very rarely. Two moments of the gap distrubiton are suggested
for characterizing an event. The fluctuations of those moments from event to
event are then quantified by an entropy-like measure, which serves to describe
erraticity. We use ECOMB to simulate the exclusive rapidity distribution of
each event, from which the erraticity measures are calculated. The dependences
of those measures on the order of $q$ of the moments provide single-parameter
characterizations of erraticity.
