The closest it is to the needle loop the less the armbar bends.if you want to understand how the whip works take a soft ruller that its 30cm or more.hold it from the bottom and swing it vigorously. The top of the ruler will swing also but it will travel a longer distance from the one your hand does and it also has greater force.
Then as you hold it from the bottom put your other hand higher on the ruler and hold it with 2 hands.if you swing it again you will notice that the swing/movement starts from the top of your hand and not from the bottom as it was before.so the top of the ruler travels smaller distance and with less force.
The same principle goes for the whip.with the clip on bottom there is more swing hence more give - power - stroke.
The closer to top = less give,less stroke,and the power only from what the motor generates.no "whip slash" effect