Bottleneck shiftiness is an important managerial problem that negatively affects shop floor manageability. It has therefore received much research attention. Yet research has focused on how protective capacity can be used to influence bottleneck shiftiness rather than on assessing its operational impact. The latter is complex to evaluate since changing the degree of bottleneck shiftiness influences utilization, which makes the results of different experimental settings non-comparable. To overcome this problem, we take a different approach. Bottleneck shiftiness is decomposed by investigating its underlying phenomenon: the impact of the bottleneck position. Using simulation, we demonstrate that tighter control can be exercised, and better performance achieved, the further upstream the bottleneck is positioned. It is consequently important to be aware of the direction of the bottleneck shift. If the bottleneck shifts upstream, performance is likely to improve rather than deteriorate as is implicitly assumed in the literature.