This document serves as the theoretical manual for the Hyperbolic Grading Simulator. We propose a rigorous unification of Item Response Theory (Psychometrics) and Special Relativity. By reinterpreting a grade not as a linear score but as a normalized expected payoff (velocity), we demonstrate an exact isomorphism between the Elo rating system and the geometry of Minkowski spacetime. We prove that while Elo competence behaves like an additive rapidity on a hyperbola, the observable grade v is its stereographic projection onto a bounded segment.
Fabrice PFAFF (Sun,) studied this question.