Thanks for the offer, but I typically find self to understand well when watching solutions. I find it to be brilliant puzzle... lots of exchanging balls/boxes! For curiousness, what does Shackle mean? Also burden? I am foreign and enjoy to learn this language. English is very big puzzle!
Thanks, that puzzle was a lot of fun to design. A shackle is a piece of metal used to lock something. In the case of a ball and chain, it would be the part fastened to the person.