In 1970, Seiko’s Daini Seikosha factory produced the thinnest automatic chronograph movement ever made up to that time: the 7017. With a thickness of just 5.9 mm, the 7017 was indeed a marvel.
The only problem was to achieve the movement’s record-breaking slimness, the engineers at Daini had to leave out all the cool looking sub-dials and registers like the ones found on their rival Suwa’s 6139 and 6138 chronographs.
To compensate, in the place of attractive sub-dials and registers, many of Daini’s 7017s sported moveable internal bezels.
Most of these rotating rings were the same unremarkable internal dive bezels found on their Sports Diver line, but a select few aspired to make up for the lack of the 7017s sub-dials with rotating chapter rings that could perform functions unavailable on Suwa’s 6139 and 6138, even with their fancy sub-dials and registers.
One of the most unusual of these was Dani’s 7017-6000 “Basketball/Soccer” chronograph.
The 7017-6000 is known as the ‘Basketball’ or 'Soccer' due to the two timer tracks on its graduated rotating inner bezel designed to time either basketball games or soccer matches.
The inner 'SOCCER' ring is delineated in alternating white and black (the color of soccer balls) for 45 minutes, the time for each half of a FIFA game.
The basketball section is marked 'BASKET BALL' and is graduated in the two colors of a basketball: orange and black. It is divided into two 20 minute sections with a ten minute break in between.
In the US, only NCAA college games are played in two 20-minute halves (rather than four twelve-minute quarters like in the NBA). Therefore the 7017-6000 would only work to time college games in the US.
However, it’s important to remember that the 7017-6000 was marketed exclusively in Japan, so it would make sense that it was calibrated to time Japanese basketball games. The Japan Basketball Association (JBA) has been around since 1930, and throughout its history its rules have differed slightly from those elsewhere. I can't confirm it, but it seems safe to assume that (if not today) back in 1970 JBA games were played in two 20-minute halves like as NCAA college games are today in the US.
But truth be told, I’m no sports fan. Basketball, soccer, football,... I never really paid attention to any of it. So I’ll never use this watch for its intended function.
I just like it because it looks good.