Thursday, April 26, 2012

How do I explain this to the children ?

My silicon chess friend often suggests moves that are hard to understand – at least for me, a mere woodchopper...

As an example, in the Pohlmann defense, Houdini recommends 6.Bb5+ (diagram) after 1.d4 d5 2.e4 dxe4 3.Nc3 f5 4.f3 exf3 ( Scheerer prefers 4...e5, but I doubt his analysis as he relies on Milov-Kramnik, 1990, but Milov could have improved by playing 7.Nb5 instead of 5.dxe5 Qxd1+ 6.Kxd1 Nc6 7.Nd5 ) 5.Nxf3 Nf6. Now I teach chess to children and I always learn them that giving a check like that is not so good, as it allows the defender to chase away the bishop with the simple c6. Applying that golden rule would indicate that 6.Bc4 is preferred over 6.Bb5+. Still Houdini recommends the latter over the logical 6.Bc4. Why ? Well, let's look at the different ways of dealing with the check.

a/ 6...c6 The most simple way of blocking the check 7.Bc4 (diagram)
The attacker has now taken away the natural black move Nc6.
...a1/ 7...b5 8.Bb3 e6 9.Ng5 b4 10.Na4 (=)
...a2/ 7...e6 8.Qe2 (+=)
...a3/ 7...g6 8.Qe2 (+=)
...a4/ 7...c5 8.Bf4 (+)
...a5/ 7...Nbd7 8.Ng5 (+=)
...a6/ 7...Na6 8.Ng5 (+=)
...a7/ 7...Nd5 8.Bg5 (+=)
...a8/ 7...Qc7 8.00 (+=)
...a9/ 7...Qb6 8.00 (+)

b/ 6...Bd7 7.Qe2 (diagram)
White develops pieces
...b1/ 7...Nc6 8.Bg5 (+)
...b2/ 7...c6 8.Bc4 (+=)
...b3/ 7...a6 8.Bxd7 Qxd7 9.Bg5 (+=)
...b4/ 7...c5 8.Bf4 (+)
...b5/ 7...e6 8.Bf4 (+=)
...b6/ 7...g6 8.Bf4 (+)

c/ 6...Nc6 7.d5 a6 8.Ba4 b5 9.Nxb5 axb5 10.Bxb5 (+=)

d/ 6...Nbd7 7.Ng5 c6 8.Bc4 Nd5 9.Ne6 (+)

So analysis proves that white gets a small advantage after 6.Bb5+. After 6.Bc4, black is able to equalise with 6...e6 (diagram).
In this position 7.Qd3 Nc6 (=) is probably best.

So Houdini was right, in this case 6.Bb5+ is better than 6.Bc4 as it denies black to place his knight on the c6 square. But as a general rule, I will stick to telling children that Bc4 is better...

Monday, April 23, 2012

Presentation by Robert Houdart

Last friday, there was a presentation In Leuven ( Flanders ) on chess engines by Robert Houdart, the Flemish author of Houdini. You can read a summary here.

It is in Dutch, but I am sure you will get the point. Really interesting stuff !

Interesting is also a grat Rybka - Houdini game :

The commentator gets lyrical about Houdini's romantic style, allowing old gambits ( such as the Blackmar Diemer... ) to be revived.

Friday, April 20, 2012

A (very) thematic sacrifice

In my book "Attack with the Blackmar Diemer", I have covered the line in the Seidel hall attack 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 Bg4 6.h3 Bxg4 7.Qxf3 c6 8.g4 e6 9.g5 Nd5 10.Bd3 Nxc3 11.bxc3 ( In an earlier blog, I indicated that 10...Nxc3 could be answered potentially by 11.00 ) Be7.

In my book, I suggested the thematic sacrifice 12.00 00 13.Bxh7+ Kxh7 14.Qh5+ Kg8 15.Rxf7 ( diagram ), but it seems black can escape with a draw after 15...Qa5 as white has no other chioce than accepting the draw with 16.Rxg7+ Kxg7 17.Qh6+

If white wants to play for a win, 12.00 00 13.Rb1 ( diagram ) might offer the best choices. But then the same sacrifice is again available in all lines.

a/ 13...b6 14.Bxh7+ Kxh7 15.Qh5+ Kf8 18.Rxf7 and black's strongest move ( Qa5 ) is not available anymore as the b6 pawn is in the way (+=)

b/ 13...b5 14.Bxh7+ Kxh7 15.Qh5+ Kg8 16.Rxf7 (+)

c/ 13...Qc8 14.Bxh7+ Kxh7 15.Qh5+ Kg8 16.Rxf7 (++)

d/ 13...Qd7 14.Bxh7+ Kxh7 15.Qh5+ Kg8 16.Rxf7 (++)

e/ 13...Qc7 14.Bxh7+ Kxh7 15.Qh5+ Kg8 16.Rf4 ( the sacrifice on f7 is not possible as white can deliver check on g3 ) and white has a draw. Obviously, 14.Bf4 is better than 14.Bxh7+, but it shows that the sacrifice is possible in all lines.

SO it seems like this is a very usefull sacrifice to be remembered !

Sunday, April 8, 2012

Odd moves in the Kaulich defense

The Brombacher counter is a great weapon for black when decling the Blackmar Diemer. Why ? Not because it is so good, just because it denies white the normal attacking patterns.

The normal line is 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 c5 5.d5 ( Brombacher counter gambit ).

Black's strongest move is now 5...exf3 6.Nxf3 (diagram), transposing into the Kaulich defense.

6...a6 (!?) (diagram) is now recommended by Houdini, but this strange move is not even considered by Christoph Scheerer. It seems to me Houdini wants to avoid some kind of "Gedult variatiation" with Bf4 and Nb5.

How should the attacker proceed ? Let's try some options.

a/ 7.Bf4 can be answered by 7...e7 and white has less than nothing (=+)

b/ 7.Bg5 is probably better than 7.Bf4 but black can chase away the bishop 7...h6 8.Bh4 g5 9.Bf2 Qb6 (=+)

c/ 7.Be3 Nbd7 (=) and white is fighting for equality

d/ 7.Bd3 (=+) gives black the luxury of choices between 7...g6 and 7...e6

e/ 7.Bc4 b5 8.Bd3 (=+) is even worse

f/ The modest 7.Be2 leads nowhere after 7...e6 (=+)

g/ 7.Qd3 runs into 7...b5 (=+)

h/ The waiting 7.a4 (diagram) is maybe best.
7.a4 alllows for white to put his bishop on it's strongest outpost : c4.
The line 7.a4 g6 8.Bc4 Bg7 9.Bf4 00 10.00 seems to give equlaity, but then again, other black seventh moves are possible.

Bottomline, the odd 6...a6 in the Kaulich defense needs to be considered carefully. More investigation is needed, but it seems another oddity 7.a4 is best.

Friday, April 6, 2012

It's a puzzle

I have been puzzled on my computer's suggestion of 7...a6 ( diagram ) in the Euwe defense, occuring after 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 e6 6.Bg5 Be7 7.Bd3

Houdini seems to like this rather ugly-looking move that neglects all development.

It goes even further than that. After 8.00, Houdini suggests at depth 20 8...Nc6 with a whopping -0.23 score ( that is : in black's favour !!! ). Hmmm.

Let's look at the standard approach of 9.Qe1 after 7...a6 8.00 Nc6. Houdini gives 9...Nxd4 and if now 10.Qh4, black prevails after both 10...c5, 10...Nc6 and 10...Nxf3+. The reason for this is simple : black has not yet castled, making the white queen on h4 look rather ridiculous.

So now I start understanding. 7...a6 is a non-committal waiting move, waiting for white to show his intentions first.

So white should refrain from playing commital moves himself, and develop quietly with moves that leave black also in the dark, eg 8.Qe2 ( diagram )

8...Nc6 is now answered by 9.000 an white has everything he hoped for. As an exmaple 9...00 10.Rhe1 ( diagram ) and white is doing fine.

So dont show your cards too quickly when the defender tries to play smart !

Monday, April 2, 2012

Why dont you capture that #&%!*? pawn ?

Every gambiteer has seen this before : you offer a pawn and your opponent refuses to capture it. You make a waiting move, and still he refuses. And finally you find yourself without waiting moves in a considerably worse position.

That's what happended to me some time ago in my match in the Belgian league a few weeks ago.

Guido De Bouver - David Molina Gomez
1.d4 Nf6 2.f3 d5 3.e4 dxe4 4.Nc3 e6
Refusing to take it

Ok, no worry, I have a waiting move

5...Bb4 6.a3
Not wanting to take it again. But I have another move.

6..Bxc3 7.bxc3 h6 8.Bh4
Why don't you take that stupid pawn !!!

8...Qd5 9.Rb1
Please, I cant stand it anymore

9...exf3 10.Nxf3
Ahhhh, finally

10...Ne4 11.Rb3
And I went on to win the endgame in 47 moves, but I can hardly say my opening was successful.

But where could I have improved ? Guess the position after 4...e6 occurs often.

5.fxe4 is probably the best move, but 5.Bg5 is more consistent with Blackmar Diemer play, after which 5...exf3 transposes to the Euwe defense.

After 5...Be7, white is forced to play 6.fxe4 whilst 5...Bb4, as played by my opponent, also calls for 6.fxe4 ( and not 6.a3 as I played in the above game ).

5...h6 is answered by 6.Bxf6 Qxf6 and now both 7.Nxe4 and 7.fxe4 are possible.

The black counterattack in the centre 5...c5 equalises after 5...dxc5 6.Qxd1+ Rxd1

5...Nbd7 is also answered best by 6.fxe4.

5...Nc6 ( diagram ) seems to be the best move for black, as it attacks the d4 pawn.
White has 6.Bb5 and 6.fxe4. We will look here at the last option. 6...Nxd4 can be met by the surprising 7.Nf3, but 7...h6 gives black a small advantage

So white has to be very carefull when black declines to take the free f3 pawn. It is an area that gambiteers have not looked at very closely in the past.

All in all, I think the straightforward 5.fxe4 ( diagram ) is simpler and easier than 5.Bg5. In fact, white has already achieved what he hoped for : opening the f file. On the other hand, white didnt get the development advantage, but still has the pawn.