Title: A New Duality Relation for Random Walks Authors: Holger Dette and Jim Pitman and William Studden Date: July 1995 Abstract: For the random walk on the nonnegative integers with reflecting barrier it is shown that the right tails of the probability of the first return from state $0$ to state $0$ are simple transition probabilities of a ``dual''random walk which is obtained from the original process by interchanging the one step probabilities. A combinatorical and analytical proof are presented and extensions and relations to other concepts of duality in the literature are discussed.