The Watch Accuracy Race: How Accurate Does a Watch Actually Need to Be?
Grand Seiko just built a mechanical watch that drifts only 20 seconds a year, the latest shot in a quiet arms race over accuracy. A working dealer's read on how the chronometer ladder actually works, from COSC and Rolex's -2/+2 to Omega's Master Chronometer and Spring Drive, why for a watch you actually wear the differences are mostly bragging rights, and where the real value still sits.