This study presents a numerical analysis of Sun-tracking strategies for flat-plate solar collectors, with emphasis on the influence of discrete rotation step size and control strategy on thermal performance. Two distinct control approaches were examined: absolute Sun tracking (aSAT), which continuously aligns the collector with the solar position, and relative Sun tracking (rSAT), which performs incremental angular adjustments. A total of sixteen configurations were simulated, combining both tracking strategies with eight discrete rotation step angles ψ = {1°, 2°, 5°, 10°, 15°, 30°, 45°, 90°}. Simulations were conducted using EnergyPlus 9.6 coupled with a custom Python interface, allowing one-minute resolution control of collector orientation. This framework enabled a detailed assessment of the effect of actuator precision on incident solar radiation and useful thermal gain. A temperature-dependent efficiency model, based on the Hottel–Whillier formulation, was implemented to account for heat losses as a function of ambient temperature and irradiance. Results demonstrate that increasing the rotation step ψ leads to a nonlinear decrease in collected energy, with energy losses reaching approximately 9% when ψ increases from 1° to 90°. The optimal balance between performance and mechanical simplicity was found for ψ = 10–15°, where the system retained over 90% of the energy yield of a continuously tracking collector. Absolute tracking (aSAT) achieved up to 17% higher daily energy gain compared to relative tracking (rSAT), especially for fine rotation steps. Although economic aspects were not included, the results provide clear design guidance for optimizing Sun-tracking mechanisms in flat-plate solar thermal systems. The developed numerical framework may support further experimental validation and the integration of tracking algorithms in low-energy and near-zero-energy buildings (nZEBs) under varying climatic conditions.