This paper investigates the use of the case-based reasoning methodology applied to the game of Texas hold'em poker. The development of a CASe-based Poker playER (CASPER) is described. CASPER uses knowledge of previous poker scenarios to inform its betting decisions. CASPER improves upon previous case-based reasoning approaches to poker and is able to play evenly against the University of Alberta's Pokibots and Simbots, from which it acquired its case-bases and updates previously published research by showing that CASPER plays profitably against human online competitors for play money. However, against online players for real money CASPER is not profitable. The reasons for this are discussed. Key words: Case-Based Reasoning, Game AI, Poker