 For the preemptive overdetermination cases, the problem is easier for the counterfactual test. Here one introduces a stipulation about the time of the event: if the defendant’s act was necessary to the house destruction being earlier than it otherwise would have been, then he was the cause, but if his act was only necessary to the house destruction happening at some time or other (including later), his act is not necessarily the cause. As the cases put this point, causes must accelerate their effects; if they fail to accelerate them (either by making no change in temporal location or by retarding them), then such factors are not causes even though necessary to when the putative effect happened (Oxendine v. State). This helps with the preemptive cause cases because a preempting fire is necessary to a house’s destruction at t1, even if (given that there is a preempted fire right behind it at t2) that first fire is not necessary either to a house destruction later (at t2) or to a house destruction sometime (t1 or t2). This stipulation regarding temporally asymmetrical necessity should be regarded as a third modification of the law’s counterfactual test.