Last Christmas, my father-in-law gave me a copy of Mancala (also known as Kalah or Kalaha). I've played it a few dozen times, but my 7 year old daughter still beats me regularly!
So I wondered about coding up the rules in GDL to see how Sancho plays it. As it transpires, a quick look in the base repository revealed that somebody had already done this back in 2009. (This game isn't on Tiltyard rotation because it doesn't contain explicit definitions of the base and input propositions.)
Enthusiastically, I fired up Sancho and got it playing. Sadly, it only managed ~100 iterations/turn. (We've made some significant general improvements since then, but Kalaha is still an order of magnitude slower even than a complicated game like Chess.) At the time, I made some tweaks to the GDL which improved the speed approximately three-fold, but that still wasn't enough for a good game.
So, it has sat on the back burner for nearly a year. Over the last couple of days, I've been digging into it in a bit more detail because I have some moderately revolutionary ideas for dramatic improvements. (Hopefully more in a further blog post.)
For now, I've produced an annotated version of the GDL which you may like to peruse. (You'll definitely want to understand the basic rules of the game first though - see the link above.)