In Reply to: This dog don't hunt posted by Sam Magarelli on November 23, 2008 at 11:43:
: What is the origin of "this dog don't hunt"?
It's modelled on the 17th-18th century phrase "that cock won't fight". In the days of cock-fighting, a cock that wouldn't fight when out into the pit was a natural metaphor for a plan or theory that simply wouldn't work. A similar sporting metaphor from horse-racing is used when we say that a plan or theory "isn't a runner". (VSD)