What is it? A fail-safe, solid, slightly wider knot
When to wear it: Anywhere – this is the all-purpose tie knot
Cross the wide end of your tie over the narrow end and back behind. Repeat. Repeat again for a wider knot. Or, holding the coil of fabric in place, run the wide part up through the loop from underneath. Pass the wide end down through the tie knot. Tighten the knot.
FYI, the four-in-hand is named after the knot used in reins to control a four-horse rig.