This is a great website. I think it would be a great idea to extend it to "knots in action" with a video showing how the forces (expected magnitude and direction) act upon each given knot. Specially the climbing ones. I few months ago I learned the knot that ties my shoes for good : https://youtu.be/aQ66r5vMqo8?feature=shared The problem with teaching knots is the hand action. Making a good knot involves good hand action. Surgeons spend months practicing sutures. There was an episode of the crime tv series Columbo where finds out it was not a suicide because the dead guys shoes where knotted backwards as someone else knotted the shoes when the guy was already dead (backwards). Very interesting.