V.    Bishop Pins.

Bishops are useful in chess tips and strategies for pinning pieces and pawns. However, Bishops may also be pinned.

One example of pinning Bishops is a Bishop faceoff (standoff) resulting in dueling Bishops where the players have placed their Queens behind the Bishops in the diagonal line creating dueling Queen-Bishop batteries (batteries are reviewed in the next section), with the players battling to seize control of the diagonal.

In this situation, both players’ Bishops are pinned against their Queens. Often this occurs in long diagonals, but naturally can occur in any diagonal line on the board. A Bishop faceoff (standoff) usually results in the players rushing other pieces and/or pawns into the battle to provide protection and defense for their Bishops. The smart player does so before creating this positional structure, because it can lead to the free capture of the opposing Bishop if the opposing player fails to adequate defend it. Bishop faceoffs often may simply lead to Bishop trades, because neither player is willing to yield control of the diagonal.

Look at the diagram below. Which of the Bishop pins is/are absolute, and which is/are relative?

The Bishop Pins existing are as follows:

***Black’s Bishops***

Black’s King’s Bishop at d4 has White’s Knight at e3 absolutely pinned. White’s Knight at e3 cannot be moved as doing so will expose the White King to check and White cannot capture Black’s King’s Bishop at d4 on his or her next move. White could move White’s King out of the pin, but this would allow Black to safely capture White’s Knight at e3 with Black’s King’s Bishop at d4 [Bxe3]. However, White can move his or her Rook at d1 to e1 [Re1] to protect the Knight, or can move his or her Queen’s Bishop at b4 to d2 [Bd2] to protect the Knight (thereby giving up the Bishop pin on White’s Knight at d5), allowing a possibility for White to safely move his or her King out of the pin. White could also move his or her Rook at d1 to f1 [Rf1], with a planned follow-up move to f2 [Rf2] to block the Bishop Pin from d4 on the Knight at e3, but this would be foolish indeed because Black’s King Bishop may then just simply take the Knight [Bxe3] or if the Knight is moved then the Rook at f2 is absolutely pinned and subject to immediate capture by Black’s King’s Bishop at d4 on Black’s next move [Bxf2].

Black’s King’s Bishop at d4 also has White’s Knight at d2 relatively pinned, because it is shielding White’s Queen’s Rook at a1 from being captured, and the Knight is subject to safe capture by Black’s King’s Bishop. White could defend and protect White’s Knight at b2 by moving his or her Queen’s Rook at a1 to b1 [Rb1], but this would give Black free capture of White’s Knight pinned at e3. Therefore, White will most likely lose one of the Knights because of the absolute pin on White’s Knight at e3 and positional inferiority.

Black’s Queen’s Bishop at f5 is not pinning White’s pawn at e4 because the pawn cannot vertically advance as it is blocked. However, White’s pawn can advance and capture Black’s Queen’s Bishop at f5 [exf5], unless Black moves it to either of two squares available…g4 or h3. If moved to g5, this would attack White’s Rook at d1.

***White’s Bishops***

White’s Queen Bishop at b4 has a relative pin on White’s Knight at c5 because Black can block the pin with Black’s other Knight at c4 [Nd6], but White could then simply capture Black’s Queen at e6 with White’s King Bishop at b3 [Bxe6] or capture White’s Knight at c5 with White’s King Bishop at b4 [Bxc5]. Black also can move his or her King to another square out of the pin, but doing so would allow a capture of Black’s Knight at c4 with White’s King Bishop at b4 [Bxc5], thereby doubly attacking Black’s King Bishop at d4 because of White’s then newly created Queen-Bishop battery (Queen at a7 and White’s King Bishop at c5).

White’s King Bishop at b3 has a relative pin on Black’s Knight at c4. Black can simply move his or her Queen to another square out of the line of attack along the diagonal, but doing so would allow White to capture Black’s Knight at c4 with White’s King Bishop at b3 [Bxc4]. Black’s King Bishop at d4 is providing some protection for his or her Knight at c5, although if White captured Black’s Knight at c5 with his or her Queen’s Bishop at b4 [Bxc5] creating a Queen-Bishop battery, and Black then captured White’s Bishop back in a Bishop trade with Black’s King Bishop at d4 [Bxc5], White’s Queen at a7 could just capture Black’s King’s Bishop at c5 putting Black’s King into check (Qxc5+), resulting in the loss of one of Black’s Knight and a Bishop for a White Bishop (not a good trade at all for Black, a loss of 3 points in material value as well as losing a valuable piece off the board) and with the added compensation of check on Black’s King.

Some additional review questions. Answers provided below.

1. Are there any other pin(s) shown on the chessboard above?
2. What is the material count for Black, and the material count for White before any further moves by pieces or pawn advances are made?

Answer to Review Question 1: White’s Queen at a7 has Black’s pawn at b7 pinned.

Answer to Review Question 2: Black has a material count of 31, and White has a material count of 37.

Challenge Question 2: Is it possible that a Bishop may be pinned diagonally so that it is entrapped and cannot move, or move and capture?