To accurately and specifically predict the reaction of someone to a situation or stimulus, showing acute insight into and observation of (or just over-familiarity with) the subject.
Named after alias of the first recorded example of "deuce-ing." Not meant to belittle the subject, but rather, to praise the observatorial powers of the deuce-er.
Place: Outside, across street from bar
Jeff and Peter observe John walking in the general direction of bar
Jeff: "Hey, ask John if he's getting a Martini or a Mimosa."
Peter: (Checks watch) To Jeff: "He'll say it's too late for a Mimosa." Yells To John: "Are you getting a Martini or a Mimosa?"
John: (Checks watch) To Peter: "It's too late for a Mimosa."
Jeff & Peter: (Laugh)
Jeff: (To Peter) "Dude, you totally deuced him."