Hisshi

I have been reading J. Tisdall's book, 'Improve Your Chess Now' .  Very good book for ideas.  In it is this idea of 'hisshi'.  The term is borrowed from shogi but that's not important.  What is important is the concept - taking flight squares form a running king.  In certain cases this can shorten a king hunt, importantly it could get you a mate where 'ordinary means wouldn't work.  I am an 'attacking' player and often follow the normal ideas of forcing moves such as captures with check, sacrifices etc.  This is a good general way of playing, because your opponents responses are limited and you can work out fairly long lines accurately.  The hisshi concept comes in as an exception and it is one of those things that once you've seen it, it looks obvious.  But when you haven't seen it, you wouldnt think of it.

A basic example of using it comes as the king is chased along the back rank, maybe by a Queen check.  As the (black) king gets to f8, you play Rf1+ , the king moves to the e-file and your attack peters out. So you 'take a move out' to play Rf1 before the queen check.  The king is then trapped, it has no flight square.

 Here is an advanced example in the form of a puzzle, and even though I have given you all the ideas, I think you will be challenged to find the answer. Enjoy

Black is in check!  Thats what is so clever, the N move is a line blocker on the b1-h7 diagonal and also reinforces the R control of d2 so if Qxe2 , Qa1 is mate , else Qxe4+, Rxe4 losing hopelessly for white.