What does ELO stand for? What does the acronym ELO stand for in the context of chess, as in the ELO rating system?
It doesn't stand for anything at all, because it's not an acronym. It should be "Elo" rather than "ELO." The Elo rating system is named after the Hungarian-American physics professor (and 8-time state champion chess master) Arpad Elo, who originally devised his rating system around 1960.