Pinning, head to tail

After the introduction of scanning as the first step in search for double attacks, I will use this blog to expand the scanning to the search for potential pins. But before I come to that I would like to spend some attention on the characteristics of the pin. This is not only useful because helps the reader to appreciate the pin as an attacking tool, but also because I read a blog of Blue Devil Knight in which the question was raised if the pin is a tactic.

The pin has three essential elements:

1. The pinning piece.
2. The headpiece (pinned piece).
3. the tail (the target behind the pinned piece).

It is deliberate that I don't speak of a tailpiece. The tail can be either of the three classic targets king, wood (piece), or (mating)square. There is another aspect that is typical for the pin. In most cases a pin can only be effective when when the tail is of higher value than the pinning piece. The exception to the rule is a situation in which the tail is undefended.

The use the pin as an attacking tool you should expand your should expand the scanning of a position with the following leads:

1. Are there targets (pieces, king or square) on the same file, row or diagonal?
2. Are these targets undefended?
3. Is the tail a target of higher value than the pinning piece?

In the next diagram it is black to move. what should he play.

To see the answer block the space between the brackets. ( If you came up with 1 ..., Rxe2 you probably wont have executed the target scan I suggested in this post and in the former post. After 1 ..., Rxe2 there are two targets in the black position that give the opportunity to win material with a pin. The tail is the mating square a6 and with the rook on e2 on the same diagonal the pin should be obvious. The exploitation of this pin is as follows: 1 ..., Rxe2? 2 Rxe2 Rxe2 3 Bf1!. 1 ..., Kb7 looks like a sensible move in the initial position. )