I only solved this as it's a puzzle, i wouldn't have seen it otherwise..>

It's something that Dan Heisman calls the "seeds of tactical destruction". Take a look at this ...

http://www.chesscafe.com/text/heism...

In short, you can train yourself to spot positions where a combination ought to be likely. In time, you develop an instinct for it...

You reach a position which starts to look tactical. You don't know what to play, but you've got this tingly spidey sense that something interesting is about to happen. The position looks ... crispy, ripe, juicy, spicy.

Here's today's starting position...

click for larger view

And the first thing you notice is that black is nearly mated. His king has no legal moves, with all of his escape squares cut off by the white rooks. What is more, white is ganging up on him. White has three pieces (K+2R) clustered around the black king. By contrasts, black's pieces are miles away.

That gives us three "seeds of tactical destruction":

1. a stalemated enemy king

2. I have lots of pieces clustered around the king.

3. His pieces are too far away to defend.

Incidentally, they are seeds that Dan doesn't mention in his list, yet they seem pretty obvious to me.

Put those three things together and you reach the inescapable conclusion that you might be able to mate the black king before his pieces can come to the rescue.

But how? The first thing to do when you've stalemated your opponent is to look for checks. Check, check, check until dead.

42. Rh6+ doesn't look as if it works. I can't see a clean follow-up. It seems instinctively wrong to all gh and open the long diagonal for black's bishop to help defend. A computer might be able to win from there, but I don't like the look of it.

The only other check is 42. Rh8+. And here pattern recognition kicks in. With 43. Kg6 we reach a classic mating position ... and a GOOT ... because the black pieces are too far away to help.

Black threatens 42... Rxf2+ and 42... Rxb3.

<Not> forced. 42...Rxf2+ is much better. But I do congratulate you for figuring out how to make the "box" symbol - the square. How did you do that?>>

I quite agree with you 42...Rxf2+ is better but only just, not 'much'.

42...Rxf2+ 43. Ke4 Re2+ 44. Kf3

and Black comes to the end of his checking. He can exchange his R for a won ending to white (which will really make it a plowman's game). But he cannot escape the inevitable.

I had gone down this route before saying a pedestrian win existed.

The other part; I'll admit I tend to use the forced symbol in nearly forced situations too. I want to say 'nearly forced' or 'almost forced' but there is no symbol for that.

I could write 'nearly instead of .

How to make the box that stands for only move?

Write like this (forced) and computer will convert it to an while printing. Just to be able to show you how it is done I have intentionally used the wrong brackets viz; ( ). Had I used the proper ones, the curly ones that look like a lady's hairpin the image would not have reached you.

(The computer is not letting me even transmit them brackets anyway, as though the enclosed a military 'Top Secret' file, so you better use the imagery I have tried to paint).

n.b Use w/o spaces around 'forced' or 'only move'.

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principle.

Hedge g7xh6 a git manage to get king back in play for h7 c3and f2 lest

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<I quite agree with you 42...Rxf2+ is better but only just, not 'much'.

42...Rxf2+ 43. Ke4 Re2+ 44. Kf3

and Black comes to the end of his checking.>

42.Rh8+! Kxh8 43.Kg6 Rxf2 44.Re8+ Rf8 45.Rxf8#

42.Rh8+ Kxh8
43. Kg6

There's no defence against 44.Re8#. (Well, 43...Re2, but that doesn't really work)

Time to check.

------------

Yes, there was no defence

Looks bored and says the position is "drawish"
Asks if you would like a cup of tea.
Suggests we might need to speed up play as they have an urgent appointment.

Asks whose turn it is.

And <self-seeds> - those thoughts that seem to hit me just before I lose catastrophically: 1. An overwhelming certainty that I have seen a brilliant move. Struggle to stop arm twitching and playing the move out of turn. 2. Vaguely wonder why they have made that pointless knight move. Probably could not think of anything useful. 3. Checked and double checked - there is no way out for them. (Followed by the unexpected - KxQ, and I have to resign).

click for larger view

42. h8+! xh8, 43. g6! ( e8#) - see below:

a) 43...e2, 44. xe2 e5, 45. xe5 mating in next move.

b) 43...xf2, 44. e8+ f8, 45. xf8#

Thus, Black has no defense against the mating threat of e8# 1-0

<42.?>

Material: White up + vs , endgame with also +3

Candidates: Rh6†, f4, <[Rh8†]>

Is there something as a position with 'too few' pieces to launch a tactical strike? In chess there is not, except for two lone kings or with either side having an extra pawn. With more pawns the breakthrough and race tactics arise, and from there on anything else we have learned.

But psychologically, the less there is on the board, the less likely we are looking at tactical blows and try to play the endgame technically. I would say White has no option to play the endgame at hand technically. The major problem is the en prise pawns on f2 and b3, the latter leading to a pretty dangerous passed b-pawn for Black. White must account for it if he wants to stay alive, and has problems saving his kingside pawns. Not pretty.

Tactics. A stalemated Black king, making the 'no tactic' part less likely. The problem for White is that the current position does require all of his pieces, the rooks and the king. The king can't mate, bringing pawns down the board seems likely but is illfated because of the rogue Black rook swooping away at the remaining kingside pawns and the White king. Hence, White has to mate with a rook.

42.Rh6† comes to mind once someone flashes this position. It is such a move that in case of the forced 42....Kxh6 Black cornered himself and White is indeed able to mate with 43.Rh8‡. Problem is, g7 is not an unmovable brick, it is a pawn, so 42....gxh6 destroys the combination there and then. The other way around then?

42.Rh8†. Weird move, for it brings the Black king further away from the White pieces, and seemingly gives him more freedom. The edges of the board are unforgiving however. After:

<42.Rh8† Kxh8 43.Kg6> it is exactly the moves White needed to waste Black. Rxf2 is no longer check, the Black king is trapped (though not stalemated, Kg8 doesn't help). Black may only decide to throw the not that helpful pieces at White before getting mated:

<43....Re2 44.Rxe2 Be5 45.Rxe5> but after that, the pieces go in the box.

Fischer vs Petrosian, Bled 1961