Python code for computing the fragility score during a chess game (Phys. Rev. E 111, 014314)

This code computes the fragility score during a chess game (given in pgn format) and shows the board and the interaction graph for the maximum fragility position. Please refer to the original publication for explanations and citations:

Marc Barthelemy, Fragility of chess positions: Measure, universality, and tipping points, Phys. Rev. E 111, 014314 (2025)