Borg Defense Trapped Piece in Chess

In the Borg Defense, a “borg defense trapped piece” is a tactical motif where the opponent’s piece (often a knight or bishop) is driven into a limited square set and can’t escape due to the structure and move order. A defining feature is that Black’s setup restricts the trapped piece’s legal moves while simultaneously threatening to win it—commonly after the opponent commits a piece to an overextended square. The result is that the piece becomes effectively immobilized, even if it isn’t immediately captured.