Early Races were largely timed by stopwatches mounted to car or truck dashboards, but as the complication was shrunk, they were much more usually noticed on wrists, especially in the F1 and endurance racing heyday among the ’50s and ’70s. This was the results of intensive R&D through the Manufacture, https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/