Divination with Sheep's Ankle Bones

I'm coming to the end of my first draft for my medieval fantasy (the dragon is slain, so it's all over bar the shouting), so I've been keeping an eye open for ideas to incorporate into my next story, which will be a Steampunk adventure set in China and Mongolia. I know the basic shape of that story, too - Miss Amelia Harper and her friend Li Bic are sent to discover the whereabouts of an expedition lost in Mongolia, and they come across a group of bandits who ambush pack trains loaded with romantic novels! This was a real thing - Chinese novels translated into Mongolian were fantastically popular, and the pack trains really did get raided by bandits. I read about it in a blog about Victorian life beyond London and the Empire, where most Steampunk stories seem to be set, and thought it was too good an idea to let go (possibly by Ayleen the Peace-Maker? I forget now). My bandits, though, are all going to be women, who want to read the romantic novels for themselves before they sell them on.
All of which is a pre-amble to a lovely snippet of information I found in a blog called woolwinding. The writer of the blog has been looking at the long co-existence of humans and sheep, and mentioned a method of divination using sheep's ankle bones which I must find a place for in my story. The bones are roughly cuboid, like dice, but with convex and concave sides, which stand for lucky and unlucky things (the horse is the most lucky roll). It's called shagai, and it all adds a bit of local colour to the narrative.