Page 17 - Peter Randall "The Craft of the Knot.."

Another term important in understanding knots is capsizing, which is
when a knot changes its shape due to a rearrangement of one of its parts
—for example, when you pull on the knot’s loop and it straightens out. If
you set up your cord and pull on the running end, it will leave the
crossing turn as it straightens and another crossing turn will form on the

cord that was running through it. This transformation can happen in
knots when they are not snugged down into their proper form, causing
the knot to “spill.” In the case of the Square or Reef Knot, this is done
intentionally, to untie it more quickly (capsizing is sometimes done on
purpose to aid in tying a knot).

When you’re making hitches, you’ll also come across “turns” and
“round turns.” These are two ways of starting a hitch around a ring, bar,
or rail. With the turn, the running end is passed just once around the
rail, which will allow a transfer of strain from the standing part to the
rest of the knot. This may be desirable for some hitches that are better

able to hold with strain on them. With the round turn, the extra turn
around the rail allows friction to help hold against strain in the standing
part, which may help when hitching a rope under strain and takes some
of the strain off the knot. The round turn is the first part of the popular
hitch called the Round Turn and Two Half Hitches.

TYING OVERHAND