At High Energy Physics experiments, extensive parallelism allows scalable, high-bandwidth data acquisition systems. On-line event building of physical events is only feasible by using switch-based event builders. The Barrel Shifter is a well-known event building method for switch-based event builders. Two nondeterministic versions of the Barrel Shifter introduced in this paper provide cost-effective alternatives to the Barrel Shifter. Simulation results are presented to show the source buffer requirements of both nondeterministic methods and the Barrel Shifter at different types of detector data flow.