Once you learn to use a chronograph watch, its busy mix of dials, subdials, scales, hands and buttons provides genuine utility and makes perfect sense.

But not always: a certain breed of these stopwatch-equipped wristwatches have a feature that’s downright puzzling. Look closely at their subdials, and you’ll find that some chronographs offer the ability to time up to a very specific number: 45 minutes. Why?

Chronographs with 30 and 60-minute timers are intuitive and plentiful, so one would assume that the use of a 45-minute counter serves a particular function. Far from a rarity or anomaly, these 45-minute chronographs were, further, relatively common for many decades — and watchmakers don’t develop and mass-produce features without good reason. Despite proliferation, however, their purpose remains the subject of speculation.

Most hypotheses focus on practical applications rather than technical benefits. A prevalent theory is that it was meant for timing soccer halves, and the once-chairman of Audemars Piguet is said to have preferred the feature for this reason. (Though in Piguet’s case, he simply demarcated a 30-minute counter with a 45-minute mark.) That would be a reasonable use of the 45-minute counter, but developing special gearing for that purpose seems inefficient when chronographs accomplish the same thing simply by adding special dial markings to 30- or 60-minute counters, as in the AP example noted above. (That said, watchmakers have done crazier things.)

There are also many examples of watches with 45-minute counters that don’t seem to have anything to do with soccer going back many decades from a range of brands — Breitling’s landmark No. 100 Chronographe-Compteur or the Universal Geneve Compur among them. Another possibility is that watchmakers simply wanted to offer more than 30 minutes while retaining decent legibility — as 60-minute counters with all those hashmarks crammed into a subdial can be hard to read. In the end, it’s likely a combination of factors.

Watch expert Eric Wind of Wind Vintage notes that while the purpose of 45-minute chronograph counters isn’t established, “part of the design of the counter demarcation may have had to do with the movement design and part of it may have had to do with the aesthetics of the register.” He also notes that watchmakers were known to modify movements to offer 45-minute rather than 30-minute counters, and this is often one of the best ways to determine the age of certain watches at a glance (for those with that level of deep knowledge).

Whatever the original purpose of the feature, some modern brands continue to go out of their way to offer it (though it’s uncommon today). For example, when Tudor used Breitling’s in-house B01 movement in its Black Bay Chrono, it modified it in several ways, including swapping a 30-minute counter for a 45-minute one and rechristening the movement the MT5813 (they also removed the hour totalizer, as multiples of 45 minutes just wouldn’t add up, of course). Other examples include modification of ETA’s popular 7750 by brands like Ball.

Chalk the mysterious 45-minute chronograph counter up to yet another quirky detail that makes watches fascinating and fun. You can happily time events and enjoy your chronograph without giving it a thought or even noticing — and most people probably do — but if your watch has this feature, timing a soccer half or other 45-minute activity just feels like you’re getting the most from it.

This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.io