This article combines Bernoulli's and Bayes's theorems to produce a tool for analyzing case-control studies whose outcomes are dichotomous. The study cohorts can range upwards in size starting at two. Tabulated examples demonstrate that the law of large numbers (which ensures that very large samples are highly representative of the populations from which they are drawn) applies only to large numbers, and not to small numbers. The article offers a simple gauge of the evidentiary strength of a case-control study. Results include demonstration analyses of real case-control statistics in the fields of posttraumatic stress disorder (PTSD), breast cancer screening and terrorism. References and tables