How many of you have used this technique, and how often? In 10 years of climbing I think I may have done it 2 or 3 times. The reason I starting thinking about it, other than being a total geek, is multiplication of forces. Nuts in opposition are subject to the same multiplication in force two anchors are subject to if the angle is greater than 90 degrees. Most instruction books show this method, and the angle usually looks close to 180. Let's say you set it up and the angle is 170. This puts 573% more force on each piece. Since most of these placements are sometimes less than ideal, which is why we think to "make them stronger" by using an opposition nut, we may actuaully be making them weaker... unless it is the only possible gear, I wouldn't use this, and am surpised that not one instructional book mentions this fall-back to opposing nuts. The book will mention the danger in angles on a two-bolt anchor if your sling is too short, and then suggest an oppositional nut placement two chapters later with no mention of the higher forces placed on the gear and rock... Anyone want to add to this geek thread?