  (Abbreviated) The detection rate of a GRB detector can be increased by using
a count rate trigger with many accumulation times Dt and energy bands DE, but
the nominal sensitivity is less important than how much fainter a burst could
be at the detection threshold as Dt and DE are changed. Predictions of the
detection rate depend on the assumed burst population, which can be wildly in
error. I base the fiducial rate on the BATSE observations: 550 bursts per sky
above a peak flux of 0.3 ph/cm^2/s averaged over Dt=1.024s and DE=50-300 keV. I
find that triggering on any value of Dt decreases the average threshold peak
flux on the 1.024s timescale by a factor of 0.6. Extending DE to lower energies
includes the large flux of the X-ray background, increasing the background
count rate; a low energy DE is advantageous only for very soft bursts. Whether
a large fraction of the population of bright bursts is soft is disputed; the
new population of X-ray Flashes is soft but relatively faint.
