Patek Philippe’s split seconds chronograph production can be split (pun intended) into two divergent camps: those with a single button operating the chronograph mechanism through the crown and those with the traditional two-button layout. The first split seconds chronograph wristwatch produced by Patek Philippe came in 1923, with a Victorin Piguet-based ebauche housed in an 18K yellow gold officer-style case. Subsequent split seconds chronographs produced in series had two buttons: the reference 1436 (about 165 total examples produced between 1938 and 1971), the reference 1563, and the unique piece reference 2512. All of these references are highly coveted by collectors to this day.

Patek Philippe wouldn’t produce another split-seconds chronograph until the reference 5959 was introduced in 2005, fitted with an all-new, in-house ultra-thin movement, the calibre CHR 27-525 PS, and housed within a 33 mm platinum case. The caliber was an extraordinary achievement in fine watchmaking history as it was the thinnest split seconds chronograph ever created at the time, as well as being the thinnest column wheel chronograph. Executed as a single-button split seconds chronograph, its design brilliantly demonstrated the prowess and know-how of Patek Philippe in the field of complications.
This exquisitely finished caliber incorporates a number of technical features (such as optimized teeth geometry and an improved clutching/unclutching system) that enable its remarkable thinness, and at the same time increase the energy efficiency and reliability of the chronograph complication. Furthermore, this was Patek Philippe’s first fully in-house designed and manufactured chronograph movement.

At Baselworld in 2010, Patek Philippe announced the reference 5950, a cushion-form, single button split-seconds chronograph with the same in-house movement but boasting subtle Belle Epoque styling. Patek Philippe launched the reference with a larger case made of stainless steel – an unusual and most appreciated decision since the vast majority of Patek Philippe’s complicated timepieces are housed in cases made of precious metals. An “application piece” reserved for the brand’s best clients, the steel reference 5950 further impressed collectors with its raised, applied black gold Breguet numerals, black lacquer scroll detailing at the corners and on the buckle, and its lustrous opaline dial. The direct inspiration for the reference 5950 can be found in the archives of the Patek Philippe Museum, with a similar single-button split-seconds chronograph cased in 18K yellow gold and bearing similar scroll details on the dial.

The current 5950A has remained perfectly preserved in its factory seal since its delivery in 2010, and comes complete with all of its original accessories.