We show how often a simple convection model can explain the structure seen in 120-eV to 28-keV particles at the inner boundary of the Earth's plasma sheet. A total of 1346 samples of the boundary were made over a 14-month period using the low-energy plasma analyzer on the CRRES satellite. The cutoff energy below which enhanced fluxes of electrons are seen during the passage into the boundary increased with L shell; the opposite was observed for ions. Forty to 50 percent of the cutoffs sampled on the nightside of the Earth were consistent with those derived from a convection model with one variable parameter. The model was normally inconsistent with cutoffs measured during increasing activity and with those made on the day side. For consistent cases a correlation of ~0.9 was found between the zero energy Alfv¿n layer at midnight and the midnight equatorward boundary measured by the DMSP satellite.