What is it?
The rattrapante, which roughly translates from French to “catch up,” is a chronograph movement with an additional seconds hand for the chronograph function superimposed over the normal seconds hand and an additional pusher. When you depress the pusher at two o’clock (as you would to start a standard chronograph), both seconds hands begin to spin the circumference of the dial in synchrony. When the extra pusher is depressed, the additional seconds hand stops. Press that third pusher again and the stopped seconds hand catches up to the other seconds hand, which hasn’t stopped moving. This allows the user to record multiple time intervals that start at the same time but do not end together (example: different lap times in a race). The rattrapante chronograph is also sometimes referred to as a double chronograph or split-second chronograph.
Where did it come from?
Nineteenth-century Swiss watchmaker Adolphe Nicole (who notably invented the chronograph reset function) is credited as the inventor of the rattrapante. In 1922, Patek Phillipe made the first rattrapante chronograph wristwatch, which in 1999 sold for over $1.9 million — at the time, the highest price for a wristwatch sold at auction. In 2016, a Rolex 4113 split-second chronograph sold at Phillips for $2.3 million, setting a record for the most expensive Rolex ever sold at auction.
Why does it matter?
Simply put, the rattrapante is very difficult to manufacture and exceedingly rare. Just a handful of manufacturers make them in-house: we’re talking the likes of Patek Phillipe and A. Lange & Söhne. But it has been produced for less. Most notably watchmaker Richard Habring developed a way to add a split-seconds module onto a Valjoux 7750 years ago while working at IWC; Habring now produces his own version under his own independent brand Habring². Still, very few manufacturers make the rattrapante. They’re worth seeking out, however — if you thought a regular chronograph was engaging to use, a double chronograph is, well, doubly so.
Who does it best?
Habring² Perpetual-Doppel

Made upon request, this rattrapante also incorporates a perpetual calendar, an incredibly complicated mechanism that rarely requires manual updating as it accounts for leap years. Despite its price tag, it’s actually an incredible value for such a complicated watch.