Short answers, pulled from the story.
Go was invented in China more than 2,500 years ago, making it the oldest board game continuously played to the present day. The earliest written reference appears in the historical annal Zuo Zhuan, dated to around the 4th century BCE, which refers to an event from 548 BCE.
A 2016 survey by the International Go Federation's 75 member nations found that over 46 million people worldwide know how to play Go, with over 20 million current players. The majority of those players live in East Asia.
Komi is a compensation added to the white player's score because black moves first, giving black an inherent advantage. Under Japanese and Korean rules the komi is 6.5 points; under Chinese rules it is 7.5 points. The fractional half-point prevents a tied result.
In October 2015, Google DeepMind's AlphaGo defeated Fan Hui, the European Go champion and a 2-dan professional, five times out of five with no handicap on a full 19-by-19 board. In March 2016, AlphaGo then defeated Lee Sedol, a 9-dan player considered the world's strongest, in four of a five-game match.
Go uses a ranking system where kyu grades run from 30 kyu down to 1 kyu for improving players, and dan grades run from 1 dan up to 7 dan for advanced amateurs, then 1 dan professional to 9 dan professional for the strongest players. The system originated with Japan's formally recognized Go schools in the early 17th century and was later adopted by many martial arts.
The players Go Seigen, a Chinese-born professional, and Minoru Kitani, a Japanese professional, are recognized as the Fathers of modern Go for their groundbreaking work on new opening theory known as Shinfuseki in the early 20th century. The names of traditional Go bowl styles, Go Seigen and Kitani, were introduced as homage to these two players by professional player Janice Kim in the last quarter of the 20th century.