It's the name given to a tactic by IM Silman in his endgame book. The basic idea is we'll say white has an outside passed pawn on the queenside and the kingside is locked up. White gives up his passed pawn to black so that he can take all the kingside pawns and easily convert a win.
Yes, what I looking for was finding someone who could explain fox in the chicken soup and you explained. I am also doing the Jeremy Silman Endgame full course
What is the fox in the chicken coupe? Please advise.