The pin is a very dangerous weapon in chess.
The Knight can not move because a
much more important piece, the
King, is behind it. The Knight has been
pinned against the King and can be
captured on the next move. It is
very important to understand that
squares protected by a piece, that
is pinned to a King, are no longer
protected by that piece. This
means that the Knight no longer guards its circle of
squares. The opponent's pieces
can camp themselves on those
squares without fear of being
taken! The knight has lost it's shape which no longer is a circle.
This diagram shows a Knight moving
onto one of the squares controlled
by the Pawn on h7. Since the Pawn is pinned
by the Rook against its King, the Pawn's
squares are no longer protected
and the King is checkmated. The Pawn has lost it's shape.
When something is pinned against the King we obtain a guarantee. The guarantee is that the pawn or piece pinned cannot move. This pin affects the rest of our opponent's army. In this diagram, even though the Pawn on c7 is pinned and cannot move, the Pawn on a7 can take the Rook.
This tells us something very simple but very very important! If the opponent is to take back then they must take back with something other than the pinned piece!
How does this help us? Well, it will help to open up avenues of attack for our army! All because of the pinned piece. In this case, the A file will be cleared of pieces and we can dream up checkmates on the A and B files.
In this diagram, White has forced
Black to advance Pawn to b6, sometime
earlier in the game. Now White
has regrouped the pieces in order
to take advantage of the hole that
was created. White has decided
to pin the Pawn on c7 to the King. Knowing
about our second guarantee,
White has moved the Knight and Rook
onto key squares. The plan is to
sacrifice the Knight for the Pawn on b6.
The Pawn on a7 must take back (Axb6) because
of Qa8 mate...and also because the Bishop pins the c7 pawn
to the King. The A file will then
be open for the Rook.
Ra8!! checkmate...because the queen sets up a barrier against the opponent's king. Another move is Qxb6!! checkmate all because the c7 pawn is pinned by the bishop.
When we play, we must struggle
to understand not only the effect
the pin will have on the
opponent's piece but also the
effect it will have on the rest of
the opponent's army.
Copyright © Manus Patrick Fealy 1994-2002
I truly want you to become a better chess player.