1. A method for estimating statistics of properties of interactions among instructions processed in a pipeline of a computer system, the pipeline having a plurality of processing stages, comprising the steps of: fetching instructions into a first stage of the pipeline; randomly selecting a set of instructions from the fetched instructions, a subset of the set of selected instructions concurrently executing with each other; specifying a distance between the subset of selected instructions; recording state information of the computer system while the set of selected instructions is being processed by the pipeline; communicating the recorded state information to software; and statistically analyzing the recorded state information from a plurality of sets of selected instructions to estimate statistics of the interactions among sets of selected instructions.