A quick Google’ing shows that this is either an “Atlantic” knot or a “Bosphorus” knot. The same Google results also open up a whole new world of tie knots! For example, “The 85 Ways to Tie a Tie” is a book based on mathematical formulation of the act of tying a tie, “equivalent to persistent random walks on a triangular lattice, with some constraints on how the walks begin and end”. The book specifies a notation used to describe how to tie a knot. I bet CK Chin has that book, ’cause I saw another pic of him with his tie tied with another fancy knot.