"There were quiet days when Kibii and I played, all during the long afternoons, a game that took me months to learn and, having forgotten it, I could never learn again. I remember only that we used the little poisonous yellow sodom apples for counters and a series of round holes in the ground for our board, and that the mental arithmetic required was more that I have since used in twenty years. We should play it in the shade of the wattle trees, or, after finishing our work with the horses, down behind the walls of the stables, sitting cross-legged over the smooth yellow balls like diminutive practictioners of black magic, waiting for a Sign. I had a small allowance of rupees from my father and Kibii had a salary of sorts. We gambled like fiends with this largesse, but neither of us established the roots of a fortune with our winnings, though a few of the coins of the realm were worn thinner.
Beryl Markham, West with the Night (1942)
Markham non specifica quante file di buche usasse, ma considerando il suo sforzo matematico, il luogo (l'attuale Kenya) e l'etnia (Murani) del suo compagno di giochi potremmo con buona sicurezza pensare al Bao.