Two ways to skin a cat...This position is from a game I was kibitzing on the web. At the present moment, white is a rook down but the black knight on b3 is hanging. If white captures the knight with QxN, then his own knight on f3 will become en prise to the black queen on f6. there is no nifty discovered attack on the black queen by moving the bishop on D3 if ever black plays QxN. However, white had a couple of good options. In the game, white played 11. Nh5! The black queen is trapped. Nasty. Interestingly enough, white also had 11. g5 with the same result. Inspite of the loss of the queen, black isnt bad at all since after 11... Qf3 12. Qf3, Nc1 13. Kg2, Nd3 black has a rook, and two minor pieces for his queen. Maybe white should play 13. Bb1 followed by 14. Kg2 to get a piece back.
When things go terribly wrong...
I had just played my knight to e4 with the obvious intent of exploting the hole on f6. It would be nice to land the grand daddy of them all, a fork of the king and queen! However, the black knight on h5 is defending f6 at the moment. It does not take a chess master to see that sacrificing the rook on h1 for the knight on h5 can make the fork come true. In this position, my opponent decided to castle --- kingside! Oh la la...Why avoid a nasty fork by stepping into another one! Of course, the rook sac on h5 was made, and after PxR, nf6+ followed and the fork became a reality.
Trapping your own Queen
In this position, black had intentions of playing Bh3 before my knight got to e4 from c3. Even without the knight on e4, Bh3 would fail to win the rook on f1 because of white's response Nh4. Black would then play his queen to f6, attacking the knight on h4 and avoid losing a piece.
Back to the position on the right, I played 8. Ne4 with the intention of capturing the bishop on d6, ending up with the bishop pair. The knight on e4 also takes away the f6 square from the black queen. Black moved 8... Nf6? With the knight on f6, the black queen is boxed in on the kingside. Black needed to keep the f6 and e6 squares available for the queen. I went after the coralled queen with 9. Nh4 and the black queen has no place to hide. White's bishop pair, the two knights and kingside pawns work together to cover all the squares in the kingside. Black had effectively trapped his own queen by 8... Nf6.