Originally Posted by Capt.aaron
It's about lifting the weight of the chain before you put any load on what ever anchor in what ever bottom type.
There is significant load on the anchor a long time before the chain lifts off the bottom. If you anchor with a fouled anchor that cannot dig in at all. The combination will drag in very light wind.
By keeping the anchor pull horizontal the chain helps the anchor work better (at low wind speeds at higher speeds it lifts off the bottom anyway), but the chain on its own does not offer much resistance.