Evolutionary computation can create a vast number of strategies for playing simple games. Analysis of these strategies is typically more time-consuming than their production. As a result, analysis of strategies produced by an EC system is often lacking or restricted to the extraction of superficial summary statistics. This study presents a technique for extracting a functional signature from evolved agents. This signature can be used as a visualization of agent behavior in games with two moves and also provides a numerical target for clustering and other forms of automatic analysis. The fingerprint can be used to induce a similarity metric on the space of game playing agents. This study develops fingerprints in the context of the iterated prisoner's dilemma but they can be computed for any two player simultaneous game with a finite set of moves.