Spring Cleaning: Knight Forks and Sac Attacks

Hi y'all! Today we are going to get rid of some pieces. Spring cleaning, what! Okay but also we are going to get rid of some of our opponents' pieces, too.

By, Mrs Jessica E Prescott (aka BoundingOwl).

The idea is to sac something to lure a heavy or a king where we want it. Next turn, a knight forks the king and queen! We will use skewers, pins, decoys, and double attacks.

Watch this simple example:

This works really well when you have a rook on an open file and a king castled kingside. See if you can figure out why!
(Gosh it would be really nice to fork on e7, but right now that would only attack the king on g8. How could I force the queen to c8?)

Great! Now it's black's turn to win a queen:

You can even sac your queen, as long as you know you're getting the material back! The following puzzle will be black's move again. Remember: it's good to force trades to simplify when you are up material. (When should you trade?)

Black will have more pawns in the endgame. And you know those mighty little pawns can promote to big queens more easily when there's no one in the way! See? Spring cleaning can be fun! Just make sure you don't toss out too many of your own guys...