This paper analyzes the stability and usefulness of a caseload management method for COVID-19 or similar epidemics and pandemics. It reduces the total cases by controlling overshoot as groups cross the herd immunity threshold, balances medical resource utilization, and subject to those two constraints reduces economic shutdown duration across significant scenario variation. A quantitative analysis of overshoot is provided. An SIR-type model was used with clear parameters suitable for public information with tracking and predictive capabilities is used. It contains a simulation of a decision-maker for select-day partial unlock so that many scenarios can be quickly and impartially analyzed. Using certain days of the week, already practiced by some countries, is not a necessary part of the method, but was used in the simulation to give a highly quantified unlock scheme. While the model shows total cumulative cases, and therefore deaths, declining initially with flattening, when flattening begins to produce large rebounds the death rate goes back up. Partial unlock to manage critical resources had the consequential effects of reducing economic downtime and bringing the cumulative cases down about 8-12% between now and the second half of 2021, thereby saving lives with some degree of certainty. The optimization of overshoot does leave some risk of creating a residual small infection existing on birth rate and migration, and we provide some guidelines for minimizing the risk.