Protected Passed Pawn Converted to Winning Diagonal Opposition

 

Lovable NYC chess coach, writer, teacher, mainstay contributor to USCF periodical Chess life Bruce Pandolfini has an extreme fondness for the term Jettison. 

In the above diagrammed position with 3 pawns per side, Blacks protected passed d5 pawn appears stuck unless one is acquainted with the endgame principle of diagonal opposition. So note that if Black plays pawn to d4 the White Monarch is forced to capture the jettisoned peon. After the Black King captures  White's f6 button, the Kings are on same diagonal separated by a single square and White's c5 pawn will eventually fall leading to a winning KP ending for Black.

In this example Bruce's term jettison essentially deflects the White King into a losing KP ending.