A REAL LIFE OFF-BY-ONE ERROR

Summary from the TLDR Web Dev newsletter

There was a subtle off-by-one error during the European Climbing Championships in Villars-sur-Ollon. A hold on the right-hand side of the wall was off by one position compared to its counterpart on the left side. Despite the error going unnoticed for years, this author spotted it because he had a reference point from a previous competition and was not visually fatigued by repeated exposure to the same wall.