This article was originally published in the May/June 2022 Issue of the WatchTime print magazine.

Zenith built the El Primero, the world?s most accurate chronograph, in 1969. But now the manufacture has increased its beat frequency from 1/10 to 1/100 of a second. We took a look at what the fastest mechanical watch can do with its many facets.

With the introduction of the first automatic chronograph caliber El Primero in 1969, Zenith already had the fastest stopwatch on the market. At a frequency of 36,000 vibrations per hour, the movement has been able to measure time intervals with an accuracy of 1/10th of a second for over 50 years. In 2017, the manufacture revived the Defy El Primero and introduced a chronograph capable of measuring to 1/100th of a second.
Now the Defy Extreme is the brand?s most modern and technical model in terms of design. Though generously sized at 45 mm across, the anthracite-gray titanium case appears slimmer on the wrist. Zenith achieves this effect with a fine, bead-blasted treatment.

Many details of this watch catch the eye. The dial is perfectly round on top but 12-sided beneath. The rectangular push-pieces are arranged in a ?V? shape and have a sloping outer edge, a groove and a protective guard that is secured with a hex socket screw (a complex shape in itself). Plus, there?s a quickchange strap system which, though undetectable from the outside, connects any of the three supplied straps to the case to...