Despite heavy competition, Audemars Piguet’s RD#5 wins this category because it represents a genuine rebuild of the complication from the ground up. It arrives in the familiar 39mm Jumbo case, yet almost everything about the chronograph mechanism has been reconsidered with a focus on precision, efficiency and ease of use.

Audemars Piguet Royal Oak Extra-Thin Selfwinding Flying Tourbillon Chronograph RD#5

The core of the project is the new movement, which replaces the longstanding hammer-and-heart reset system with a rack-and-pinion solution. This change is significant: energy is accumulated during operation and released in a single controlled action at reset, allowing the hands to return cleanly without vibration. It also makes possible a true instantaneous jump for the chronograph minute hand. The aim is not visual drama, but accuracy in how elapsed time is recorded.

The coupling system follows the same logic. Instead of a complex multi-layer vertical clutch, RD#5 relies on a simplified approach in which the pinion moves vertically to engage or disengage the chronograph. This removes the start-up hesitation often seen in traditional builds and reduces energy loss. A column wheel oversees the start, stop and reset sequence, maintaining consistency in operation.

The watch also addresses the way a chronograph should feel in everyday use. Modern chronographs typically require a firm push with noticeable travel. Here, AP has reduced both. The pushers have a short, precise movement and require far less force, making start/stop/reset more direct. The goal was practical: to create a chronograph that responds cleanly without demanding effort from the wearer. It is a simple change, but it alters the relationship between user and mechanism in a way that is easy to appreciate.

The 39 mm titanium case is paired with a bezel, push-pieces and crown chip in BMG (Bulk Metallic Glass)

Despite the technical rethink, the watch retains the proportions associated with the Jumbo. The movement sits within an 8.1mm high case, even when combined with a flying tourbillon. Space is saved through careful architecture and a peripheral rotor, which also opens up the movement visually without adding thickness. The use of titanium for the case and bulk metallic glass for the bezel and pushers keeps weight down and gives the watch a discreet but contemporary feel.

The Calibre 8100 introduces a flyback chronograph with a patented reset mechanism

Taken together, these developments explain why RD#5 stood out in a category judged on timing precision, chronograph construction, coupling method, energy management and tactile performance. The watch does not chase spectacle; it focuses instead on how a chronograph records time, how it draws power and how it behaves when activated. Each decision serves the same purpose: to make the complication more reliable, more consistent and more intuitive.

In recognizing RD#5, the award highlights a chronograph that advances the complication rather than giving it a facelift. It is a thoughtful piece of engineering housed in one of watchmaking’s most recognizable forms. The result is a chronograph that feels both familiar and newly resolved, demonstrating how targeted changes can shift expectations for how a mechanical timer should function today.