april 22 2014
Daniel's word
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).
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.
Master's words
Five 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.
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?
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.
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.
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.
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.
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=
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.
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 !
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
R6) 7:Bh5 Kb1 8:Kc3 Re5! (8:...Kc1 9:NcK threatens Nb3) 9:d7 Rd5! 10:d8=Q Rxd8 11:Nxd8 Kc1=
7:...Rb4
R7) by the nice manoeuvre 7:...Rd4 8:Bh5 Ka2 9:Bd1! Ka3 10:Kc3 Rd5 11:Kc4 +-
8:Na5!
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!
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
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+
19...Ng5+
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.
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...
** 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.
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