A realistic setting for Feynman paths

In the context of quantum mechanics, the physical origin of the wave function or probability amplitude is unknown, only the square modulus having a direct interpretation. Similarly, the path integral is considered a calculational tool with little connection to any external reality. Here we consider a counter-example to this general picture. We discuss a reformulation of the Feynman chessboard model which is completely realistic, allowing an examination of the physical origin of phase and Feynman paths in this simplest of cases.