Tactical or positional example? You decide.

White to play and win. Tough nut to crack.

Originally posted by Mephisto2
White to play and win. Tough nut to crack.

[fen]3k4/2pq3p/pp5R/4P3/P6P/2PN4/1PN3K1/8 w - - 0 1[/fen]

this is too hard, any clue for the clueless?

Originally posted by robbie carrobie
this is too hard, any clue for the clueless?

Imagine a position where two knights and two pawns can immobilise a queen. Hence the title 🙂

Does it start with 1 Nd4 Qg7+ 2 Kh3 Qxh6 3 Nf4 followed by Nde6 and Ng5?

Originally posted by mcreynolds
Does it start with 1 Nd4 Qg7+ 2 Kh3 Qxh6 3 Nf4 followed by Nde6 and Ng5?

Your first moves are correct. Ng5 isn't necessary. Another move is required, though.

ps. Note that 1.Nd4 Qxa4 2.Rxh7 wins for white based on material plus, so after 1.Nd4, black has nothing better than Qg7+.

e6 followed by e7?

I'd find that to be very annoying, if not totally sound

Originally posted by Tiwaking
e6 followed by e7?

I'd find that to be very annoying, if not totally sound

You mean from the start position?
Let's see:
1.e6 Qxd3 2.e7+ Qe8



White is lost. If he tries to save the knight, then Qd2+ loses the rook.

Originally posted by Mephisto2
Your first moves are correct. Ng5 isn't necessary. Another move is required, though.

ps. Note that 1.Nd4 Qxa4 2.Rxh7 wins for white based on material plus, so after 1.Nd4, black has nothing better than Qg7+.

ok then... based on what mcreynolds started ...

1.Nd4 Qg7+ 2. Kh3 Qxh6 3.Nf4 K-somewhere (c8) 4.Ne6 (barricades the black queen) c5? 5. h5! (protecting pawn with knight, allowing the King to move) then your King is off to the races (Kg4 Kf5 etc.) eh?

It seems like it'll take quite a few moves to get the passed pawn though. But it does look like whites position will win. It helps that blacks other pieces are hog-tied, so he'll be forced to make a few King moves he doesn't like. I tried a few times on the board and it seems to work, but too embarrassing to post the lines.

Nice problem, took me a while even when mcreynolds solved most of it.

Originally posted by allostery
ok then... based on what mcreynolds started ...

1.Nd4 Qg7+ 2. Kh3 Qxh6 3.Nf4 K-somewhere (c8) 4.Ne6 (barricades the black queen) c5? [b] 5. h5! (protecting pawn with knight, allowing the King to move) then your King is off to the races (Kg4 Kf5 etc.) eh?

It seems like it'll take quite a few moves to get the passed pawn though. But it does loo ...[text shortened]... g to post the lines.

Nice problem, took me a while even when mcreynolds solved most of it.[/b]

Correct, h5 completes the blockade and frees the white king. It can take a while indeed, but white can treat the queenside like a normal winning pawn ending, forgetting all the pieces on the kingside.

Brilliant, isn't it.

Why is the endgame won? Black's queen is trapped away from the action but White's Knights have to stay in place to keep her there, White's king goes to the queenside but so does black's? Can someone play it against an engine and post the PGN?

Ok I just tried it against the chessmaster on quick time controls and won pretty easy despite the fact I suck at endgames. It is interesting because I let it evaluate the initial position for a while and it didn't think much of 1. Nd4, preferring 1 Rf6 or 1 Kf3

Originally posted by mcreynolds
Why is the endgame won? Black's queen is trapped away from the action but White's Knights have to stay in place to keep her there, White's king goes to the queenside but so does black's? Can someone play it against an engine and post the PGN?

The two knights, albeit being forced to stay in place, still take away enough squares from the black king, especially to knight on e6, to allow white to easily win an opposition battle. The white king penetrates via the centre and gets an easy promotion, with enough tempi ahead of black. Try it yourself, it is really easy.

edit. meanwhile you posted a possible follow on yourself. Better than if anyone else had done it 🙂

edit 2: yes , this problem has been known to be a tough one for the computers too, with some exceptions. Most programs don't 'see' that the position is a simple endgame. That's why I challenged the term '100% tactic' in other threats. This is positional.

Originally posted by mcreynolds
Why is the endgame won? Black's queen is trapped away from the action but White's Knights have to stay in place to keep her there, White's king goes to the queenside but so does black's? Can someone play it against an engine and post the PGN?

Winboard was useless, but when I play it out it seems to finish with a white pawn that has a clear route to the house.

1) black can only move the abc pawns and the King
2) white controls c5, c7, and the d-file

There are some options but here's what I could come up with (the engine was useless):

[FEN "3k4/2pq3p/pp5R/4P3/P6P/2PN4/1PN3K1/8 w - -"]
1.Nd4 Qg7+ 2.Kh3 Qxh6 3.Nf4 Kc8 4.Nde6 Kb7 5.h5 c5 6.Kg4 c4 7. Kf5 Kc6 8. Ke4 b5 9. axb5+ Kxb5 10. Kd4 a5 11. Kd5 a4 12. Kd4 Kc6 13. Kxc4



EDIT: whoops, you beat me to it. I like yours better.

Hi Meph.

After you gave to solution I was going to suggest you show
it with the pgn moving thing thingy. But I see another lad has done this.

Was this Rinck he did loads of Rook and 2 Knights V Queen studies.
Though the ones I know were mostly pawnless.

Just had to go and look this up could not recall the exact postion.

This is not in the same class but has a nice 'Eh!' moment as it flies
in the face of everything we know.

For best effect just click 'play'.
Then do it a move at a time and you will see it's forced.

White to play and win. (3 moves max).


No trick. It's mate.

Hi

You know sometimes a pieces of music can take you back and you can
recall the exact moment where you were when you first heard it?

That pawn formation that appears in one of the posted solutions



I've never forgotten it.

I first saw it in a Korchnoi - Petrosian game (1973) in a newspaper column.

I was still a bit wet behind the ears then and when I played out the game
I was totally amazed that Korchnoi had seen so far ahead because he allowed
a big swap off on the Kingside to leave just this pawn formation and the
two Kings.

It was quite a moment. That pawn formation always drags me back there.

It was a Saturday and I was drinking coffee in a cafe waiting for my girlfriend
who worked there to finish.

I had a pocket set with me because I had been bitten by the Fischer bug.
(everybody was) and played out this game (it was an English) that I doubt
I understood.

Even now I cannot understand a Korchnoi game.

Years later of course I realised it was a technique thing and once you see
the idea you never forget it.
And I have won a couple of games with this very idea.
(then told the same dull story).

This is not the exact position but you will see the idea.



I still have that pocket set. 🙂