This article discusses the challenges posed by the scope and volume of the evidential record to fact-finding and the presentation of cases in international criminal trials. To this end, it introduces a modified version of a technique first developed by John Henry Wigmore at the start of the 20th century, which provides a device for mapping complex arguments based on mixed masses of evidence. The potential benefits of the method to both lawyers and judges are illustrated with examples from international criminal trials. This discussion is timely, given a recent debate that has arisen in international criminal law on the analysis of evidence in general, and the standard of proof to be applied to individual facts in particular. The article concludes by offering some observations on that debate and arguing in favour of a method that might be seen as excessively fragmentary to some, but ultimately enables a rigorous analysis of the arguments that support or weaken conclusions on the guilt or innocence of the accused.