Hickford et al. in the orginal article. Best summary is probably the below. https://people.maths.bris.ac.uk/~majge/hjce.06.pdf https://people.maths.bris.ac.uk/

Hickford et al. in the orginal article. Best summary is probably the below. https://people.maths.bris.ac.uk/~majge/hjce.06.pdf https://people.maths.bris.ac.uk/~majge/hjce.06.pdf We observed knots forming at the ends of the string (chain in this case) vs in the middle. I can imagine adding 'hook shapes' at the ends of the chain, like headphone ear buds or connectors on a cable in the pocket would increase the likelihood of knotting. Thanks for the interest.