Max Carrados is a blind amateur detective genius, quite popular in the early 20th century, but mostly forgotten since then. (Such is also the fate of E.B.'s Kai Lung fantasy stories.)

In this story, involving two mathematicians, Max is challenged to expose a card-playing automaton. [[An alleged analytic engine, and an even more alleged Charles Babbage, make their appearance.]]

**Note: some may consider this last sentence a spoiler. I cannot figure out a way to convey the mathematical content without giving away some of the surprise. Part of the surprise, of course, is this is a c1920 story. Is it the first computer in fiction?**

First reprinted in THE EYES OF MAX CARRADOS (1924), later reprinted in a Dover collection of Max Carrados stories.