Targets

I have previously described an 'ideal target' as a piece which is both unprotected and immobilised.

Spotting simple cases of immobilised pieces is quite straight forward - they have no free squares to move to. Identifying them and unprotected pieces is becoming part of my routine when looking at the board.

As I begin the forth pass of Reinfeld, I am stopping to deliberately name each feature of the position by tactical motif when doing the review problems - "This piece is pinned, there's a barrage, the King is exposed...", and as I work through the solution "X-ray on the pinned Queen, Black plays Queen takes Queen, White plays the Zwischenzug Rook takes Rook check, then recaptures the Queen.".

Now I want to start relating more complex forms of 'unpotectedness' and 'immobilisation' to the tactical motifs - ultimately they are one and the same thing.

Reinfeld position #20
White to move

The Knight at d5 is unprotected because the Rook at d6 immobilises the Pawn at c6 by a pin, and the Bishop at e6 by an X-ray - if it moves the Queen forks the King and the Rook at f6. This makes it easy to find 1. Bxd5 capturing the piece which has been left unprotected despite having two 'defenders'.

Reinfeld position #880
White to move

Here we see the King is exposed and has limited mobility. 'Exposed King' is another way of saying 'unprotected' since the King requires blockers (ie a castle), 'defenders' are pointless since it cannot be exchanged! If White can control f8 forcing the King to e8, it will also be immobilised whereupon we need only find a suitable check and it will be mate. 1. Rxf4 annihilating the defence (Bd6) 1. ... Qxf4 2. Bb4+ Ke8 and the first goal is achieved. Now if only we can make that check, the cost is immaterial. 3. Qxe6+ decoying the f7 pawn from protection of g6 (clearance of the h5-e8 diagonal) 3. ... fxe6 4. Bg6#.

Pinning is an obvious form of immobilisation. A piece being overloaded takes a little more work to identify, but it unprotects one of it's defensive tasks by being called to act on a different one (the f7 pawn in the second example). Interference is a simple form of blocking the line of a defender so unprotecting its charge, whereas Zugzwang unprotects by forcing a piece to use its mobility against its will.

This relationship between targets, unprotectedness, immobilisation, and tactical motifs needs to be clearly defined and incorporated into the method of looking at the board.

Oh, and I rather stupidly copied something from GM Averbakh without thinking it through for myself and adapting it to the context of this discussion... there's quite an important tactical idea missing.

5. CAPTURE THE ATTACKING PIECE!

Duh.