Ideally you have two anchors out at twice the distance apart that you need for a safe anchorage, middle yourself between them, break the cables and inser a swivel .
As most yachts do not have joining shackles in their cable, normally one just puts up with the fact that each turn of the tide makes another step in tying a wondefful spaghetti know in the chain.
It was a technique developed in the RN when we had so many battleships there wasn't a bay big enough for them all to lie at single anchor. This way you could cram them in closer.
I'll tell you, with 12 ton anchors and chain links 4" across it was a by-our-lady nightmare.
It's so associated with US yachts unused to tidal currents, anchoring in the Bahamas, that I had no idea it was RN originated.
You are quite right about the tangle. There is a technique for sorting it out that involves pushing the yacht round in circles using the dinghy. The habitual US yachtsman in the Bahamas has this down to a fine art. Each morning a busy anchorage is full of buzzing outboards on gyrating dinghies.
Quite agree with Bill - 'Bahamian mooring indeed!!' - It was used in the Merchant Navy (when we had one) to moor in narrow rivers and the like. We used to call it a dropping moor or a running moor, depending on which anchor you dropped first.
We won the quiz (strangely enough i knew the answers to the golfing questions) but the team beat up the yottie for not knowing this fancy name - I've always thought off this as simply a second anchor to reduce swing.