Abbe and I discuss playbook information in connection with COI in ULE at p. 259. The idea originated in a discussion by Richard Zitrin at a Hofstra Ethics Conference. Richard is both an experienced litigator and avid poker player, and talked about the importance of the tell – information about how a player reacts in critical situations. He then related this to information gained in a former representation about how the former client reacts in negotiations and litigation, e.g., a disposition to settle (and for how much) rather than litigate. The idea was endorsed, also at a Hofstra conference, by Chuck Wolfram, who referred to it as playbook information.
Today's NY Times (5/1/12) has an obituary of Amarillo Slim, "poker's first superstar," who won five World Series of Poker. "Poker players," he said, "should concentrate on their opponents more than their cards" -- agreeing, in effect, with the importance of playbook information.