Actually, cases of causal preemption are good cases to use to illustrate why some counterfactual theorists like Lewis think causation should be analyzed in terms of the presence of a chain of counterfactual dependence. We have already noted that the case of Billy and Suzy is a problem for the regularity theory of causation since there is regular nomic succession of rock-tosses like Billy’s and window-breakings and yet Billy’s throw is not a cause of the window’s breaking.