Get the latest tech news
Byoyomi Explained (1997)
ritish Go Journal No. 106.
My sources were videotapes of the Kisei and Meijin games of 1996 and a 1977 magazine article in Gekkan Gogaku on the topic of time keeping. That is why game records (e.g., in the Igo Yearbook) often show that a player took 7 hr 59 m. It is not possible to take the full 8 hours of an eight-hour time limit. At least, it was in the twenty-year-old article I found in Gekkan Gogaku describing timekeeping for a minor game with a five-hour time limit.
Or read this on Hacker News