Page 63 - Buck Tilton - Outward Bound Ropes, Knots, and Hitches 2 ed.

Bring the doubled working end over the doubled

standing part.

Whatever the name, it ties with relative ease and works
well in diameters of cordage ranging from fine thread to

thick rope. It also ranks high as a secure loop: Once tied, it
stays tied. Even so, knot experts argue over whether or not

the figure 8 loop should be finished with a stopper knot in
the working end, a procedure that would eliminate any
chance the figure 8 could slip. A stopper can be added with

ease if the working end is left long enough. Those who
argue against the stopper point out that the figure 8 loop,

after being weighted, often proves difficult, but not
impossible, to undo.