The pause is in the most difficult position of the lift. In a three-digit tempo prescription, the first number is the eccentric contraction (lengthening of the working muscle), the last number is the concentric contraction (shortening of the working muscle), and the middle number is the pause and it's location depends on the lift. The pause would be at the bottom in a bench press, so after the eccentric. The pause would be at the top in a chin-up, so after the concentric. Three-digit tempo prescriptions can be a bit confusing.
I went into a longer explanation in this thread:
http://forums.jpfitness.com/new-rule...trophy-ii.html