The simplest way to make a looper is to remember for the base to go right the prongs on the right must be shorter. Then for the base to go left the prongs on the left must be shorter. You can bend the prongs backward to make them shorter or which might be a better solution. Pull or flatten out to prongs that you want longer.
Here's a summation of what was included in the Tudor Rules book in the late 60's:
A base’s speed or strength maybe increased or decreased by either brushing the prongs forward or to the rear. For speed the pongs should be positioned straight but angled back ever so slightly. To get more strength they should be brushed backwards.
If you want a base to turn in an arc, brush the prongs back on the opposite side you want it to turn. Then brush the other legs forward. For example to make the base turn right, brush the left prongs back and the right prongs forward. Just do the opposite if you want the base to go left.
If a base is running in a circle and you want it to run straight. Brush the legs back on the side which it is turning and brush the legs forward on the opposite side. An example of this would be if the base is circling right. Brush the right prongs back and the left prongs forward on the opposite side.
The same rule can apply to a base that veers hard to the right. Lightly brush the prongs on the right side back and lightly brush the left prongs forward.
It seems that very few ever read these tips.
wbj