Corresponding work distributions and standard deviations of work distributions are shown in SI Figures . For trials using 1000 NCMC switching steps and more, the uncertainty was calculated based on blocking. The number of blocks used was the amount that maximized the standard deviations of the acceptance rate across blocks. For trials using fewer than 1000 NCMC switching steps, accepted moves were rare enough that we took the standard deviation across four trials and computed the standard error from that.