More details about the The Rapala Knot
Uses: The Rapala Knot is a non-slip loop knot intended to be tied directly to the lure. The Rapala brothers recommended it for use with their Rapala lures as providing a loop which allowed the lured to move freely and naturally.
They also recommended that if a swivel or leader is essential, it is best to choose the lightest tackle possible. This allows the lure to move with a natural motion.
Tying it: A long enough loop should be left to ensure that the lure is not gripped.
Advantages: The advantage claimed for this knot is that it allows the lure to move naturally. It is also claimed to retain most of the line strength - and this might be expected as the structure of the knot passes the force to the loop via a wrap in the center which distributes the force to the loop.