The Impotent Pair refers to a RP and Bishop of the "wrong color" that does not control the queening square. If the lone King cannot be prevented from arriving at the queening square ahead of the enemy King the game is a draw. In this diagram the position is a stalemate with Black to move and drawn game otherwise. Be on the lookout for this drawing possibility when you are losing even if there are several other pieces on the board, you can always try to trade down to this ending if your opponent has never heard of it - like I did in an OTB tnmt game many years ago.