Pins


Pins are an extremely important tactic to be aware of. Just as important as knowing how to set one up, maybe even more important, is knowing how to avoid them. That's why it is so important to look at what the board will look like after you make a move and what your opponent's move may be. So, before you place a piece of lesser value in front of a higher valued piece, check to see where your opponent's Bishops or even Rooks are located. Are you setting yourself up for a pin, either on the next move or shortly afterwards (ie a pawn or another piece moved out of the path of a Bishop or Rook)?
And a pinned piece may be unable to defend. Smothered mates are often achieved when a pawn is pinned to the King and cannot take the attacking Knight.
And situational pins may not even look like a pin - at first. Before moving any piece, be sure you aren't opening yourself up to a pin or a skewer (think of it as a reverse pin where the important piece is in front). In the diagram below, should White take the Bishop - Nxd5? I mean, it's just hanging there, right. What a gift! But look what happens to the b file. Wide open!! And look who's waiting to move at b8. Rb1+ forces the King to move and just look what happens after that - Rxh1. That "free" Bishop cost White a Rook.