november 26 2013

For this new session, the core group is growing as the number of auditors stabilizes at 4 active members.

The first and second positions are the exercises given by the Master in the previous session.

1 - white plays and threatens to win !
Valery P. VLASENKO
Jubilé Association Russe des amis du problème-80, Shakhmatnaya Kompozitsiya 2006
Honor Mention

1kNB3b/8/8/2p5/8/2p2K2/6B1/8

W : Kf3 Bd8g2 Nç8
B : Kb8 Bh8 Pç5ç3

+ (4+4) C-
Why threatens ?
Because the study is simply incorrect.
However, its incorrectness is quite subtle and deserves attention.
The Master adds a correction at the end of this report

The second one is, a priori, correct (unless you demolish it of course)
2 - White to play and draw
David GURGENIDZE
ChessStar 2009
2nd Prize

3K4/1P5r/k7/8/7p/8/1R6/7r

W : Kd8 Rb2 Pb7
B : Ka6 Rh7h1 Ph4

= (3+4)

The 3rd position is an endgame where black plays it with finesse

3 - Black to play and win
Fidel - Ramis 1980

7k/3PK3/1p6/1P6/8/8/8/5q2

W : Ké7 Pd7b5
B : Kh8 Qf1 Pb6

(3+3)

Did you know what a "negative" (Knight) Rosace is? I didn't know either. I just learned it with this amusing (and not so easy) h#3. Another "crazy story" with a surprise. In the h#5.5, it's not easy to guess the square where the bK will be mate. The last helpmate has something in common with the first two, while being... the easiest of the four!

  
Everything is prepared in the 2#. So what's the deal? The first 3# is a festival of batteries, the second a festival of sacrifices. We know the Plachutta theme, but its inventor prefers... the swallow. The other 5# shows... the hare and the tortoise. The 7# is a festival of returns. Finally, an astonishing selfmate that I don't think is well known. I forgot to remove the solution, but you can open the diagram, hide with your left hand what's on its right, lower it gently, and then click on "practice", just above the author's name.
  
There is a well known case where Bishop and Knight win against a single Bishop. Here is a new illustration, with an additional precision... but patatras! I discover nightly that it is insoluble. Never mind: we only have to turn it over; we obtain a draw study with two variants.

  
A repetitive phase in "King David", that's normal. But preparing a nice point on the 8th move. A secondary variation transposes into a very small part of an extraordinary composition by a little known Latvian, whose surname is regularly butchered, Hans Seyboth (1864-1938). The final phase of this masterpiece is our exercise 205. In the same variation, I must rectify what I thought tonight: that after 9...Kb1, both 10 Rf2 and 10 Rh8 drawed, whereas this last move is losing on 10...Re3! (we had only considered the return 10...Rh1?).
  
There is such a thing as a draw in an endgame where the cybernetic monsters give a 7.24 rating. And more often than you might think. 
A missed aesthetic move in a game of two colossi, although the result would have been the same. With, to please the problemists, a thematic try.
  
It is not only in the 1991 Short-Timman game, which has been quoted extensively for the last twenty years, that the White King rises in the middle of a melee of heavy pieces. A classical plan struggle in the middle, then a surreal pawn race. A clarification: in the 33...f5 34 g4 Qd7 variation, rather than 35 Rxc5 Rb7, convincing is 35 gxf5! Bxf5 36 Rxf5! followed by the exchange and the pawn tide. 
  
See you at the fairy session in a fortnight' time, on Tuesday 10 December. May God keep you. 
  
Have a good feast.

I don't remember ever showing an incorrect study in St-Lazare session, except in cases where the demolition seemed as interesting (or even more so) than the solution, which justified the selection. What happened, I don't know: I often cut the "machine" to try to think for myself, but I put it back in fine. Mystery...
  
When the 4...c4! defence was pointed out, I replied that it amounted to a move switch. But no, because by taking the b3-square, Black cuts the path of the wN to c1 (via a5) and thus threatens ...Kb7. It is therefore necessary to play 5 Bc8, which would indeed be a reversal on 5...c1Q? But the bK has no more escape square, which Black exploits: 5...c3! 6 Ke4 Bc1!! with stalemate blackmail. John Beasley, publishing the study in his former BESN, saw nothing but fire, as did I! My "denial" occurred last night, at 2am: the duck confit puts in shape.

  Fortunately, this nice move allows the study to be turned around while keeping something presentable. The author's try becomes a variant, and his main variant becomes a try! What do you think of this? Too bad you have to stop at the 7th: I liked 9 Bd8!!!, but there is a dual with 8th. 
  
It seems to me judicious to quote, besides obviously the Lazarian team, the said confit as co-author. 
  
Have a good two-way feast.

An elegant end game for the fourth

4 - white to play and win
Gligoric Portisch 1971 

5rk1/R6p/1p2p3/2p4p/2q4b/2P2Q2/5PP1/3R2K1

W : Kg1 Qf3 Ra7d1 Pç3f2g2
B : Kg8 Qç4 Rf8 Bh4 Ph7b6é6ç5h5

(7+9)
 

The key makes it possible to shorten the game as it really took place, where White had played Ra8

now, the 2 exercises for the next session

5 - exercise 1 for next session : only winning move

8/1K4k1/5b2/B7/P7/8/8/8

W : Kb7 Ba5 Pa4
B : Kg7 Bf6

+ (3+2)

6 - exercise 2 for next session White to play and draw
Sergeï DIDUK

K1k5/P7/1p6/2p5/1P6/8/1bP3P1/8

W : Ka8 Pa7b4ç2g2
B : Kç8 Bb2 Pb6ç5

= (5+4)

for the game of the day, a nice fight between 2 monsters

7 - game of the day
1.d4 Nf6 2.ç4 ç5 3.d5 é6 4.Nç3 é×d5 5.ç×d5 d6 6.Nf3 g6 7.g3 Bg7 8.Bg2 0-0 9.0-0 Na6

9. ... Nbd7 is more flexible
10.h3 Nç7 ?! 11.é4 Nd7 12.Ré1
12. ... b5 13 e5
12. ... Né8 13.Bg5 Bf6 14.Bé3

Bishop comes back after having disorganized black a bit
14. ... Rb8 15.a4 a6 16.Bf1 Qé7
16. ... Nc7 17. Bf4
17.Nd2 Nç7 18.f4 b5 19.é5

Thematic move in reply to b5
19. ... d×é5 20.Ndé4 Qd8 21.N×f6+ N×f6 22.d6 Né6 23.f×é5 b4 24.Nd5 N×d5 25.Q×d5 Bb7 26.Qd2 Qd7 27.Kh2 b3 28.Raç1 Q×a4 29.Bç4 Bç8 30.Rf1 Rb4 31.B×é6
31. Qd3
31. ... B×é6 32.Bh6 Ré8 33.Qg5 Ré4 34.Rf2 f5 35.Qf6 Qd7 36.R×ç5 Rç4 37.R×ç4 B×ç4 38.Rd2

White player zeinot
38. ... Be6 39. Rd1 Qa7 40 Rd2 Qd7 41. Rd1 Qa7
White realizes that he has exceeded 40 moves
42. Rd4! Qd7 43. g4! a5 44. Kg3 Rb8 45. Kh4 Qf7 46. Kg5! fg 47 hg Bd7 48. Rc4!
chameleon echo of the 42nd move !
48. ...  a4 49. Rc7 a3 50. Rxd7! Qxd7 51. e6 Qa7 52. Qe5! ab 53. e7 Kf7 54. d7! abandon
An intense fight

For the agape, a small Petkov for Julia

8 - h#2 with neutral chinese pieces
Petko A. PETKOV

W : Kb6 Ré6 Pç6
B : Ké3 Pd6d4é4d3d2f2
N : Nç8 Paoç4 Va8

h‡2 (3+7+3)
b)Pf2-->f3
c)Pf2-->f4
N=chinese nightrider : nightrider needing a sautoir to capture
P=Pao : Rook needing a sautoir to capture
V=Vao : Bishop needing a sautoir to capture

To help you a little, in the position, black is mate if you remove e4 and f2

A little diversions through Sentinelles

9 - h#2 Sentinelles with twin
Hans Ultenbroek

2b5/8/8/3n1p2/4k1p1/5R2/r7/r2R1K2

W : Kf1 Rf3d1
B : Ké4 Ra2a1 Bç8 Nd5 Pf5g4

h‡2 (3+7)
a)Sentinelles : a piece defecates a pawn of its colour on each move (except for pawns)
b)adverse pawn Sentinelles : a piece defecates an opponent's pawn on each move (except pawns)

Very cute

And finally, the Mars Circe!

10 - s#30 Mars Circe
Gerard SMITS

R7/8/1P6/1r6/1P2NP2/5K2/P5P1/7k

W : Kf3 Ra8 Né4 Pb6b4f4a2g2
B : Kh1 Rb5

s‡30 (8+2)
Mars Circe : the moves are normal, but the captures are done by virtually passing through the original square

Not too possible for the neophytes, so here is the beginning of a solution and an explanation

1.Nç5 Ra5 no capture possible, square a8 is not free
2.Ra7+ virtual passage through a1
2. ... Kh2 3.Ra6+ virtual passage through h1
3. ... Kh1 4.a4 white was able to play a "real" move !

For the rest, you are on your own!

That's it, the verbatim report is finished.
I refer you to the electronic version of the Master, which is much more complete and above all more correct!
Next course on December 10th.

Good reading to all.
Sincerely yours

Le greffier