Monthly Archives: February 2011

A moment in the solid Sicilian

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I’m thinking about a position in the Scheveningen Sicilian, however you say it…

http://upload.wikimedia.org/wikipedia/commons/5/55/Nl-Scheveningen.ogg

Sicilian = sharp+theoretical

Chess Stars
Easiest Sicilian = Sveshnikov
Safest Sicilian = Taimanov
Sharpest Sicilian = Najdorf

A move order for Black in the Classical:

6…Be7 no reason to delay this
7…0-0 well, you can delay this move!
8…Nc6 the best squares

Now there is a big split here for Black:
9…Qc7 (idea …e5)
9…a6 (idea …b5)
9…Bd7 (idea …Nxd4, …Bc6, …Qd7 and …b5)
9…e5
9…Re8

--------
--nppn-p
pppbbqp-

-kr----r

I think the safest and most solid move is 9…Qc7. It holds back White’s e4-e5 move and threatens to play …e5.

Now, …e5 is often a good idea in the Scheveningen. We have learned that in a lot of Sicilian lines, the d6 pawn is not weak and occupying the d5 square is not much of an achievement. The d6 pawn is difficult to attack and a Knight on d5 can be swapped off, even if it manages to co-ordinate with White’s other pieces.

Meanwhile, Black gets a big pawn in the centre, which is supported (unlike White’s e-pawn). White’s Bishop on d3 or f3 suddenly gets blocked in. Black gets other options, like playing …e5xf4 and …Nf6-f7-e5, with a great Knight outpost. So, although this is complicated and you need to be careful, you shouldn’t be afraid of playing …e5. Spassky even showed us that you can play 9…e5 straight away! But I like 9…Qc7 first.

First of all, I think you will get some White players who will think you have made a mistake and play 10.Ndb5. Of course, you will play 10..Qb8, then 11…a6 and after 12.Nd4, the Queen has moved, the a-pawn has moved, but the Knight is back where it was! So, you have gained two moves, thanks to White, and they are good moves to make; your Queen is still thinking about e5 but can also now support …b5.

Secondly, the most straightforward way to get an advantage

If these positions are a bit too dull for you — f you think they don’t give you enough chances to win with Black — then you need a slightly riskier line. I recommend 9…a6.

The simplest mutual full-point Zugzwangs

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Tim came to the club buzzing with these a few weeks ago.

[Skip intro]

A Zugzwang (German: forced move) is a chess position where, if it’s your turn to move, you lose, and if your opponent has the move, you might be OK.

Here’s an example from one of my own games: anything White does loses. We say, White is in Zugzwang.

Black can doodle happily with pawn moves, but any move of a white Pawn or piece loses at least a Pawn. White in fact threw himself on the sword with
43. c4 Ra3+ 44. Kh4 Be7+ 45. Kh5 Rh3#

The simplest Zugzwang position of all is known from the theory of Pawn endgames, with two Kings and one pawn trying to promote.

Black to move loses, but with White to move, it’s a draw.

A mutual or reciprocal Zugzwang is where neither side wants to move, and this position is indeed a mutual Zugzwang.

A mutual full-point Zugzwang (m-f-p-Z) is where both sides are in Zugzwang. In the Pawn endgame, White to move concedes a half-point to Black, but in a m-f-p-Z White loses a whole point. Here’s an example, known as the trebuchet:

All OK? So, these ideas have been around for dickey’s years, but what Tim was enthusiastic about was learning of positions with King each, a Pawn each and a single white piece (Bishop, Knight or Rook), which met the conditions of a m-f-p-Z. In fact, Tim was more mischievous than just to show us: he set us the task of finding the positions! I’ll give you an hour or so now to have a go yourselves…

(…)

Finished? How many did you get?

Solutions for 5-men positions:

Bishop:

A couple with a Knight:

and

Rook:

Nothing so simple exists for a Queen, but if you are prepared to add extra pawns, or an enemy Queen:

and

Here are solutions for 6-men positions with B N or R:

and

or

And if you have a Rook each, we have examples like:

More?

Full set:

http://www.k4it.de/egtb/zugzwang.php/

Article about 6-man tablebases:
http://ticc.uvt.nl/icga/acg12/proceedings/Contribution104.pdf

John Nunn got a bit interested in all these, and I refer you to his excellent books based on comprehensive computer endgame databases, recently updated since the emergence of the 6-man tablebases:

P.S.

Candidates for the Immortal zugzwang game include this classic from Nimzowitsch:

Samisch – Nimzovitch [E06] Carlsbad, 1923

And two he would rather forget:

Nimzovitch,A – Capablanca,J [B12] New York, 1927

Alekhin – Nimzowitsch [C17] San Remo, 1930

All are to be found in the Canon:

P.S. in 2026: a complicated mfpZ

https://chess.stackexchange.com/questions/9062/full-board-with-full-point-mutual-zugzwang

Noam Elkies chipping in tuppence there