Table 1.

The number of simulations required to find rare trajectories (at least once) given a specific likelihood and assuming a binomial distribution (across simulations) where a success is defined by the presence of the end-of-chain risk

Likelihood of a trajectory	Representation in the simulation	Simulations required to find trajectory (95% confidence)
0.500	Reference likelihood	8
0.444	Observed level of inadequate infection control	9
0.100	Reference likelihood	46
0.010	Reference likelihood	473
9.45×10−3	Precision chosen in experiments	500
0.001	Reference likelihood	4742