Squeezing the dynamic killbox

I use a problem set with a lot of sacrifices around the king. Of course you have the usual tactics, which we all know. What we do need most, though, is to identify the logical scenarios that are involved. A useful metaphor is to identify the killbox that the king is in, and to build your logic around that.

White to move

r4rk1/pbq2pp1/1p1b4/4B2p/7P/2PBQ2R/PP3PP1/R3K3 w Q - 1 20

Janowski, Dawid Markelowicz vs. Saemisch, Friedrich, Marianske Lazne 1925

One square is not accounted for: h8. Yet you have already a piece in place to cover that: Be5.

• 20. Qh6! f6
• 21. Qh7+ Kf7
• 22. Bxd6 Qxd6
• 23. Re3

Look how the killbox is morphing. 

Black to move

These moves are not the only way to win. But I want to show you how the killbox evolves over time. It requires a different way of thinking. The tactics are subordinate to the killbox. Just like the tempo moves.