Rate of thermonuclear bursts as a function of inferred accretion rate for selected neutron-star binaries from the MINBAR sample. The top panel shows the measured rate for 4U 1636–536, which reaches a maximum of 0.6 hr⁻¹ at an accretion rate between 0.05 and 0.07 of the Eddington rate, while for 4U 1728-34 (bottom panel), the burst rate increases gradually over the entire range of accretion rates observed. The rate calculated within each accretion rate bin is from 50 bursts, and the uncertainty is estimated assuming Poisson statistics on the number of detected bursts.