I may know where the confusion is coming from. One of our local pro shops has been referring to an old wall chart for years that uses the center of the grip as the point of reference for degree drillings. This gives you a completely different layout than the current dual angle system that most pro shops are now familiar with. The dual angle system uses the pin as the point of reference for angle drillings, not the center of grip. I'm going off the top of my head here, but I believe a 90 angle drilling using the dual angle system will probably put the MB in about the same position as a 120 degree drilling using the old wall chart. This is a rough estimate of position. The link below will take you to an image of the old chart I am referring to.
http://cdn.bowlingball.com/images/conte ... 3-bias.jpgScott Hewitt
MOTIV Bowling