april 22 2014

Daniel's word

Rémy being, alas, still prevented, and under the threat of the probable absences of Marc and Grégory, I had revived Antoni so that the lesson could proceed normally.
In other words, so that someone could actively participate in the research proposed by the Master, an activity which reaches my limits when it is alone and which therefore goes beyond these limits when I have to note down variants.
Antoni came, as agreed (thanks to him) and, O surprise, Marc managed to free himself! (always with the constraint of having to get up the next day, well before potron minette).
Homework correction.

White to move. Position taken from an analysis of a Degraeve Bologan game played in Belfort.

It is obvious that if W's do nothing, B's will win by Kf5-g4-g3 threatening Kg2, the W's will have to play Kf1 and will be mate after Kf3 and e2#.
Even if they are difficult, studies (in the broad sense of "studied positions") where the plans are clear are easier to look for because you don't risk going astray for 10 moves without even knowing if you have played the right first move.
This is the case for this position, as well as for almost all the positions given in home exercises.
It can therefore be used as a support by anyone who wants to teach their students to analyse.

Once you have studied a few short variations, you will be convinced that Bb4-c5xe3 or Bb4-d6xf4 do not work, nor does the Pa's push from too far away.
The logical conclusion is that if a defence exists, it consists in opposing this RN manoeuvre. And everything becomes simple.

1:Kf1! Kg4 2:Kg2! preventing Kf3 and Kg3 and B cannot progress because when they push f3, this f3 square is no longer available for the bK.
2:..f3+ 3:Kf1 Kg3 4:Bd6+ Kg4 5:a4 or Bc5 followed by Bxe3 and a4.
Black to move. Position from a variation of a Goloshchapov - Tregubov game.

Master's words

Skripnik 2Five helpmates for Daniel to distract him from his incessant computer repairs. And to get him through... a full month! The first one can make you think, as well as the 5th solution of the 3rd. The second is a duplex: White is also checkmated in the W-B-W-B-W-B pattern.
J halumbirek

I follow them with two 2#s, one of which is a classic. The other one, interesting as it is, has a slight flaw, but which one? Then two 3# of very different styles. A 4# (with twin) with a fun asymmetry. A moremover and two selfmates. Two solutions faded badly...

One can be ranked 2650 by judging a winning position with a Bishop and a King, against a phalanx of pawns, as a loss.

Can a rook catch two pawns? It depends on how the accompanying King is led. Note the difficult trial ...Kg4?   

Iglesias 3

A composition by our (only?) French study composer, repairing and improving a demolished work.  

For all tastes: an etude beginning with a wild struggle to bring an endgame zugzwang.

Beliavsky 6Shirov 8

The game of the day is a festival of provocations by the unchained White King. With an "anti-dual" effect at moves 14-18. And an exaggerated severity of the commentator (White's player) on his own choice in the endgame.

A little rest: see you, God willing, in a little more than a month for the last "normal" course of the season, on Tuesday 27 May (the fairy course being scheduled for 10 June).     
Have a good time.

Among the 5 candidate moves a4, axb, Kf3, Kg4 and Rf3, only one is winning. Which one, and how?

This exercise is very difficult. The difficulty is not to understand that the good sequence wins, but to find why the other sequences do not win because the candidate moves are multiple and one loses quickly in the analyses. On the other hand, these analyses are very useful to do because they allow to "revise" some classical winning or draw positions.
Where Rémy's superiority is obvious is that in such a position, I did not manage to follow all the variants and to note those which were essential to synthesise the analysis. I therefore refer to the electronic report of the Master.
To get to the point, This is the reasoning one would have to follow if one had this position in a game and wanted to have a chance of finding the right path, without mastering the analyses (if one is not able to calculate very quickly and very well, it is better to reason correctly).
1) It will obviously be necessary to bring back the bK to fight against the P. By where, g4, f3 or f4 after having played Rf1 or Rf3 ?
2) In addition to all this, should we play axb4 or is it better to leave the a-pawn which could in some cases go to promotion or in other cases serve as support for the T on the b-file?

I didn't manage to solve this exercise because I was (wrongly) winning with the B's both by Rf3+ and by Kf3. And this because I had answered question 2) by saying to myself that the Pa could be useful to me in the fight against b5 and c6.... which was true but which forgot that an essential defence of the Bs consists (often) in playing b4xa5 in contempt of the beautiful organization of their pawns!

The reasonings held more by reflex than by reflection make us keep linked pawns to fight against the velocity of a rook, BUT they should also tell us that to fight against Rook AND King, the best is to have a pawn as far away as possible from the opponent's R!

Thus, do not go :
1:...a4? 2:b5 Rf3 3:Kb4 Kf4 4:c6 Ke5 5:c7 Rb3+,6:Kxa4 Rc3 7:b6=
1:...Kf3?! 2:bxa5! (which had escaped me) Ke4 3:Kc4 Ke5+ 4:Kb5 Rf1 5:a6=
When one has understood this, question 2 is settled, the first move is better understood.

1:..axb4 2:axb4.

and it only remains to answer question 1) by calculating some simple variants.

2:...Kg4?! it is necessary to bring back the K and the idea to keep the horizontal cut is tempting, but it runs up against the unfortunate position of the bK on the diagonal c8-h3 where it will be check on the promotion of the "c" Pawn. 3:c6 Rf1 (3:...Kf5?? would easily win if it were not for 4:c7! and the bK's position prevents both Rf8 and Rf1)
 4:b5 Kf5 5:b6 Rc1+ 6:Kb4 Rxc6 7:Kb5=

2:..Kf3!! 3:c6 Ke4 4:c7 (or 4:Kc4 Ke5+ 5:Kc5 Rf1 and win) Rf1 5:Kc4 Rc1 and win
Studies of the day.
White to play and win
For a change, here is an unpublished study by an excellent French composer (who is also an excellent player).
I can't help but offer this thought that came to me while writing:
There are people who publish more than they compose (this is plagiarism)
People who publish as much as they compose and who are right,
People who publish as much as they compose and who are quite wrong,
People who publish less than they compose and are right (they are demanding)
and people like Joachim who publish much less than they compose and who are quite wrong.
After Wotawa ...
As I may have the chance to publish this study in Phenix, I will try to make the solution understandable by as many people as possible.
The key cannot be understood without first asking why not 1.Kb4? Ke7 2.Rxa2 Kd6 3.Rc2 Rc7 4.Rd2+! (a manoeuvre that often appears in the solution) Ke6 5.Ka5 and win.
So how do the B's defend themselves? They would obviously have to bring their K in front of the wP. But how? To ask the question is already to answer it. 1.Kb4? Ke7 2.Rxa2 Kd8! 3.Ra8+
(3.Rc2 no longer has the same efficiency Rc7 4.Rd2+ Kc8) 3...Kc7 4.Ra7+ Kb6! and the bR is taboo;
Hence the idea to avoid the return of the bK by avoiding the stalemate
1.Kb3! Ke6 Because now, after 1...Ke7 2.Rxa2 Kd8 3.Ra8+ Kc7 4.Ra7+ there is no more stalemate, as Pb5 is not yet defended !.
1...Rb7 2.Kb4 Ke6 3.Rxa2 Kd6 4.Rc2! Rc7 5.Rd2+! already seen
2.Rxa2 Rc7 To bring back K with Kd7 and Kc8. Note that on 2...Kd6!? 3.Ra6+ (3.Rc2? doesn't work because K is not yet on b4, so 3:..rc7!) 3...Kc5 4.Ka4 Rf1 5.Rc6+ Kd5 6.Ka5!;
Or 2...Rf4!? 3.Rd2 Re4 4.b6 Rf4 5.b7 Rf8 6.Ka4 Rb8 7.Rb2 Kd6 8.Ka5 Kc7 9.Ka6 just in time.
3.Rd2!! (3.Kb4? Kd7=) 3...Rd7 4.Rc2 Rd4 Threatens .....Kd7=
And now a hard-to-find move.
How do you make progress knowing that you are not going to neither 5.b6? Rd6! nor 5.Ka3? Kd7! 6.b6 Rd6.
5.Rc7!! Kd6 (if 5...Rd6 6.Kb4 or 5...Rd7 6.Rc4 followed by Kb4) 6.b6 Rd1 7.Kb4 Rd5 8:Rc8. 1–0
O. Pervakov and K. Sumbatyan.
White to play and win.

A study that can be found... when one looks for it during the course and is guided by the Master who keeps us from false directions.
I will therefore try to bring a little help of this nature to the possible interested reader, knowing that nothing beats for that the verbal exchanges which have the immense advantage of being interactive. (conclusion: come to the classroom!).

The black threats are such that it is necessary to be active and concrete

Q1) what are the 3 candidate moves ?
Q2) What are the black responses to the tries 1:Qh8 and 1:Qa8 ?
R1) Qa8, Qh8 and Qg7.
R2) 1:Qh8? Qg4!;  1:Qa8? Qxf7!
1:Qg7! Rf4 (what W win on 1..Qxf7?)
Q3) Why 2:Qg1+, followed by Qh2, doesn't go ?. So, what is the move?
R3) 2:Qg1? Bf1 3:Qh2 Rf3 4:Bb3 Rxb3+!
Q4) What to do? What are the 2 candidate moves ? What is the defference Be2 and Bc2?
R4) 2:..Bc2 allows 3:Qxc2 Rf3+ 4:Bb3
2:..Be2! Qxe2
Q5) What is the value of 3:..Rf3 and 3:..Qh3 ? And so what is the B move ?
R5) 3:..Rf3+ 4:Qxf3. 3:..Qh3+ 4:Bb3
3:..Qa4+! 4:Kxa4 d3+  What is the only W move ?
5:Qe4 (5:Kb3? dxe) Kxe4+ 6:Kb3 d2  7:Kc2
Q6) Which move would allow B to get away with it after 7:Bh5? Kb1 8:Kc3

R6) 7:Bh5 Kb1 8:Kc3 Re5! (8:...Kc1 9:NcK threatens Nb3) 9:d7 Rd5! 10:d8=Q Rxd8 11:Nxd8 Kc1=

Q7) How does W win after 7:...Rd4?

R7) by the nice manoeuvre 7:...Rd4 8:Bh5 Ka2 9:Bd1! Ka3 10:Kc3 Rd5 11:Kc4 +-

Q8) How does B draw after 8:Nc5?

R8) 8:Nc5? d1=Q 9:Kxd1 Rd4+ 10:Kc1 Rc4+ 11:Kd2 Rd4+ 12:Kc2 ( catches the N-square!) Rxd6 13:Nb3+ Ka2 14:Nd4+ Ka1= and you can see the point of having the c2-square occupied!
8:...d1=Q 9:Kxd1 Rd4+ 10:Kc1 Rd3!

Q9) What would be the W win after 10:...Rxd6?

In the solution, how do the B's draw after 11:Bc4? or 11:Kc2? or 11:Be6?
So what is the W-move?

R9) 10:...Rxd6? 11:Nb3+.
After 10:Rd3 11:Bc4? Rxd6 12:Nb3+ Ka2 13:Nd4+ Ka3 14:Nb5+ Kb4 15:Nxd6 Kc5= or 11:Kc2? Rxd6 and the square c2 is occupied, or 11:Be6? Rxd6 = there is no more discovery chess.
So :
11:Bg8! Zugzwang Rxd6 12:Nb3+ Ka2 13:Nd4+ Ka3 14:Nb5+ Kb4 15:Nxd6

. 1-0.
Homework for next session.
Exo 1.
White to play and draw
Exo 2.
White to play and win
Game of the day.
Beliavsky - Shirov
Study on the comparative efficiency of different battery types.
1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Ndb5 d6 7.Bf4 e5 8.Bg5 a6 9.Na3 b5 10.Bxf6 gxf6 11.Nd5 f5 12.Bd3 Be6 13.Qh5 Rg8
I don't know anything about the theory, but it seems that this move is not played anymore. It would be played o-o or c3 instead.
I understand that Tg8 was played by Leko, but this was probably in a game that did not reach me...
14.g3 o-o seems to be the other big move. The theory doesn't seem to consider o-o-o followed by f4 blowing everything up, but the theory certainly has its reasons.
14...Nd4 15.c3 fxe4 16.Bxe4 Bg4 17.Qxh7 [17.Qh4?! would be to Black's advantage after Nf3+ 18.Bxf3 Qxh4 19.gxh4 Bxf3 20.Nf6+ Kd8 21.Nxg8 Bxh1]
17...Rg7 18.Qh6! While on the same suite with o-o instead of g3, Qh8 would be good and Qh6 bad, here it is exactly the opposite.
18...Nf3+ 19.Ke2! Beliavsky said that this was not a home preparation. Let's bet that currently the preparations on this would make at least 10 more moves.
I noted that there were big complications after 19.Kd1 Ng5+ 20.f3 Rg6 21.Qh4 Nxe4 22.fxg4 Nf2+

It is easy to understand why the players were in zeitnot. Indeed, a player like Shirov necessarily sees a large number of monster variants that he must judge, and Beliavsky must also see them to avoid disasters. Here is an exciting example of what the players have to see that completely eludes the spectator watching or replaying the game:
19...Rh7? 20.Nf6+! Qxf6 21.Qxf6? 21...Ng5+ 22.Ke3 Nxe4 23.Kxe4 Be7! à la Shirov!
but alas refuted by 21.Bc6+! Ke7 22.Qxf6+ Kxf6 23.Bxa8+-

20.f3 Nxe4 Here is an example of the variations found by the small but good audience: 20...Rg6 21.Qh4 f5!? 22.fxg4? Rh6! found by Antoni whereupon a Shirov defence was found by Marc: 23.Nc7+ Kd7 24.Ne6! There's plenty of time for the course!

21.fxg4 Qc8! [21...Rxg4 allowed 22.Qe3! to the W advantage.] 22.Qe3 Qxg4+ 23.Qf3 Qxf3+ 24.Kxf3 f5 25.Nc2 Kf7 26.Nce3 the position is satisfactory for the N, but time is running out.

26...Ke6?! Shirov prefers to sacrifice a P to keep complications. Better was 26:...Nf6
27.Nxf5! Taking up the challenge in zeitnot! Tall and slim, Beliavsky shows Shirov that he is not dealing with "un nain gras"...
27...Ng5+?! [Better was 27...Nd2+ 28.Ke2 Kxf5 29.Kxd2 Ke6! 30.Ne3 d5! with compensation] 28.Kg4! When we tasted it...
28...Rf7 29.Rhf1 Ne4 30.Rad1 Raa7 Rc8 with idea Rc4 seemed more interesting
31.Nde3 Rad7 32.Kf3! Battery default
32...d5 33.g4 Bc5 34.h4 Nf6 35.Rde1 b4 [35...Bxe3 36.Rxe3 Rc7] 36.Re2 time crisis [36.cxb4! Bxb4 37.Rc1 Rc7 38.g5]
36...bxc3 37.bxc3 Bxe3 38.Rxe3 Ne4 [38...Rb7] 39.Kg2 Rc7 [39...Rb7? 40.c4!] 40.Rb1 Rb7 41.Rb3 Nd2 42.Rxb7 Rxb7 43.Re2 Nb1 44.Rc2 Na3 45.Rf2 Nb1 46.g5 Nxc3 47.g6 Rd7? Ne4 was better and even made it possible to hold
48.g7+- Kf7 49.h5 [49.Kh3 Ne4 50.Rg2] 49...Kg8 50.h6 Kh7 51.Ne3 1–0
And finally, the fairytale position of the dinner.
helpmate 2 moves Kobul Kings with neutral Locusts 2 solutions

** Helpmate : The Ws and Bs cooperate to achieve the requested goal. Here, the Bs start and help to make the second W move mate.
** Kobul Kings : When a piece is captured, the king of its colour captures the march of that piece, until another piece is captured.
** Locust: A piece (marked L) which moves along the Queen's line, jumping over a piece of the opponent's colour, its arrival square being the square immediately following the sautoir, provided that this square is free. At the end of the move, the sautoir disappears. A Locust can therefore only play by capturing.
To sum up, the locust needs a sautoir, eats the sautoir and lands right behind it.
** Neutral piece. This is a piece that can be played by either side, when on the line. A neutral piece can capture and be captured. A side may not let its King be captured by a neutral piece (just as it may not let its K be captured by an opponent's piece).
*** Mixing neutral piece and Kobul Kings: if a neutral piece is captured by a move played by the W's, it will be considered that the captured piece was playing at this moment the role of black piece and so the bK will take the march of this captured piece. In the same way, if a neutral piece is captured during a move played by the B, the captured piece will be considered white and the RB will adopt its march. 

Let us see our problem:
Black, to move, can play :
Lb3xb4-b5, i.e. the locust b3 goes to b5 eating the locust b4 which serves as a sautoir.
Lb4xb3-b2 i.e. the b4 locust goes to b2 by eating the b3 locust which serves as a sautoir.
Kc8, or Kc7, but not Kb7. Kb7 would be illegal because the K would get caught by the b4 locust.

Now that things are clearer, what might the mate board be?
** It seems impossible to checkmate the bK if it moves like an R.
So it will have to move like a locust to be checkmated. This is made possible by the Kobul Kings condition.
** But then, for the bK to acquire this march, a locust must be captured by the Ws.
** We can therefore imagine 2 moves of black K to go and stand on the square where he will be mate, a white move (which one?) then finally a move Locust captures locust played by the Ws which makes mate.
** But then, how can the neutral locust attack the bK who moves like a locust without the latter being able to capture the locust himself?

It is impossible, although most of the reasoning is sound. You just have to be even more clever in exploiting the rules.

white Ke5 black Kb8 neutral lb3b4
b3, b4: Locustes neutres
right side of the board to advance and left to retreat or directly on the move

. Let's look at our problem:
The Bs, on the line, can play :

} 1.Lb3*b4-b5 [e5=rL]+ {i.e. the locust b3 goes to b5 by eating the locust b4 which serves as its sautoir.
} 1.Lb4*b3-b2 [e5=rL]+ {i.e. the locust b4 goes to b2 by eating the locust b3 which serves as its sautoir.
} 1.Kb8-c8{, ou} 1.Kb8-c7{, mais pas } 1.Kb8-b7{. Kb7 would be illegal because the K would get caught by the b4 locust.
Now that things are clearer, what might be the mate board?
** It seems impossible to mate the bK if it moves like an K.
So it will have to move like an K. So it will have to move like a locust to be mateable. This is made possible by the Kobul Kings condition. ** But then, for the bK to acquire this march, a locust must be captured by the Ws. ** We can therefore imagine 2 moves of black K to go and stand on the square where he will be mate, a white move (which one?) then finally a move Locust captures locust played by the Ws which makes mate.
** But then, how can the neutral locust attack the bK who moves like a locust without the latter being able to capture the locust himself? The thing is impossible, although most of the reasoning is sound. You just have to be even more clever in exploiting the rules.
Let's look at the first solution: (I remind you that it's an aid, so it's the Bs that start).

} 1.Kb8-c7 Ke5-f5 {(it is necessary to stay on the 5th to allow the second W move. This is the only move that allows the Ws to pass their rook without degrading their possibilities).} 2.Lb3*b4-b5 [f5=rL]+ {(check to wK) As this move is a black move, the captured locust at b4 is a white sautoir, and so the white K catches the march of the captured locust.} rLf5*b5-a5 [c7=rL] # ! { Great! The wK moves like a locust. He captures the locust b5 which is considered a B sautoir, so the bK inherits the locust's march. He is checked by the locust king a5 without being able to either flee (no free sautoir) or capture a5 for lack of a free square behind this potential sautoir.
I leave the reader to discover for himself the second solution which is the perfect echo of the first solution. All diagonal effects become orthogonal and vice versa !
Key is :
} 1.Kb8-a7 !


(Personal notes for the Master, to enrich what has been shown at the dinner :
it seems to me that the first W-move in the second solution has no other purpose than to pass its rook, whereas in the first solution it is necessary to play the W-move because if the Ws could pass their rook, the second B-move would be illegal!
Moreover, it is an aid in which the white moves are not so constructive as it seems to me also to be reverse 2 moves helpmates. I would even go further: in the second solution, B could play 2 serial moves and W would be obliged to checkmate in 1. And if I am right, it is quite a defect for helpmate)


Potron-minette, when it comes from Marc, is tasty...

The analysis of the 1st exercise is perfect, but it is useful to specify that the difference between the good move and the bad ones is a whole point, not half a point as it is usual...

In exercise 2, the most complex variation is missing, where the GM leading White went wrong: 1...Kg4? 2 c6! Rf1 3 bxa5! Kf5 4 c7! =

The 5 categories of study composers detected by the Acting Master Greffier are a luminous summary of the greatness and decadence of French artistic composition.

Excellent presentation of the Wotawa-Iglesias study. The 2...Rf4 variation in my review needs to be extended a bit. So does the main variation. I give it again for possible editing in "phx".

Pervakov's masterful explanation (in the parenthesis of Q6, it is 9 Cc5). I didn't see any mistake in the psychedelic game of the day.

Quite agree with the criticism of the fairy helpmate. Strange that the helped-selfmates (or rather, self-helpmatee) are so fashionable that they come back to bother us where they don't belong!

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