**Exo2**.

White to play and win (from the no less great Pervakov).

I had also looked for this exercise.

As with the previous one, I didn't find it, but here the position is sufficiently complex that I didn't for a moment have the idea that I had demonstrated anything (except a certain weakness).

The B's threaten (among other things) to capture the Qd8 or to play a1=Q or to mate by 1:...g2+ 2:Kg1 Qh2#.

1) So I obviously considered 1:Qxc7 Rxc7 2:a8=Q (which has the advantage of warding off the main threats) 2:...g2+ 3:Kg1 Rc1 4:Nxf3! (not 4:Ne2? Bg3+! 5:Nxc1 f2#) 4:...Bg3+ 5:Ne1! and wins.

I thought to myself that this didn't look like a solution and that something (an B-resource) must be missing.

Indeed, the preceding variation is well forced until the 3rd move, but after that the B's have a better suite.

2) I looked (and I also advise the reader to look) if there were other candidate moves (in the first move).

Indeed, there is a very strong W-move which equals all the threats stated above and which moreover threatens strongly.

1:Qg5! certainly, this move page g2+ in a very effective way. Moreover, it threatens mate in 1 move.

I will now indicate what I had found at home. Obviously, if I give the following variation, although it is not the solution, it is because it is absolutely essential to see it to understand and appreciate the solution.

1:...Qf4! 2:Qxf4 g2+ 3:Kg1 Bf2+ 4:Kxf2 g1=Q+ 5:Kxg1 a1=Q+ 6:Kf2 Rc2+! 7:Ne2 and I leave it to the reader to find out how the B's draw in 3 moves in a forced way.

3) This is therefore not the solution since the B's draw. But the solution is a refinement of this variation.

1:Qg5! Qf4! 2:a8=Q! (why?) Rxa8 3:Qxf4 and play the variation already seen.

The reader will easily see how putting the Rc8 in a8 changes things. Finally, the reader will remain vigilant in the manoeuvre of his K at the end of the variation to win with Q against R and P.

**Game of the day.**

It opposes Karpov to Kamsky at the time when the latter was the rising young prodigy (with a father who pissed everyone off).

**1.d4 Nf6 2.c4 g6 3.Nf3 Bg7 4.g3 c6 5.Bg2 d5 6.cxd5** Karpov is a player who is in no particular hurry to smooth out the position, so one wonders why this exchange which seems to eliminate tension.

The Master gave an answer during lesson but I have not managed to write down the reasons in enough detail to report them here. Basically, it comes out that the W's have no good move other than this one in this position; 6:Nbd2 running into Bf5 followed by who knows what else.

6...cxd5 7.Nc3 0-0 8.Ne5 to try to oppose Nd7 and drive B to play e6, conceding Ws some space advantage.

8...e6 9.0-0 Nfd7 10.f4 Nc6 11.Be3 Nb6 12.Bf2 Bd7 Previously, against the same Karpov, Kasparov had tried 12:...Ne7 with the idea of countering B's e4 by dxe4 and occupying the d5 square.

13.e4 Ne7 14.Nxd7 Qxd7 15.e5 Here is a good example of Karpov's contribution to the strategic conceptions of the time. The closure of the centre does not bother him despite his two Bs behind the pawns. 15...Rac8 deciding which R to put on c8 is a matter of taste. Depending on whether one prefers to keep a R on the "f" file or to clear f8 to play Bf8.

Note, for the attackers, that Karpov indicates an idea on Rf-c8 which impressed me a lot: 15...Rfc8 16.g4 Bf8 17.f5! gxf5 18.Be3! (why not Bh4, by the way) followed by 19:Bh3! the take on g4 leaving the Pf7 very exposed.

**16.Rc1 a6 17.b3 Rc7 18.Qd2 Rfc8 19.g4 Bf8 [19...f5 was strongly to be considered.] 20.Qe3 Nc6 21.f5! a move that requires precise calculation on the kingside but especially on the queenside and in the centre as the B's next move continuations must have been correctly judged.**

21...Ba3 22.Rcd1 and now the undefended Nc3 seems to allow the B's several combinations, but neither Nxe5 nor Nxd4 goes because of the undefended Nb6! 22...Nxd4? 23.Qxd4 Bc5 24.Qf4 Bxf2+ 25.Qxf2 Rxc3 26.Qxb6.

22...Nb4 23.Qh6! and Nc3 is not immediately capturable because Nb4 prevents the return of the B to f8 to parry the mate after f6. If 23.Nb1 Nc2! 24.Qh6 Bf8.

**23...Qe8 **Karpov had planned 23...Nd3!? 24.Nxd5! Nxd5 25.Rxd3 Bf8 26.Qg5 which indeed seems dissuasive, but the Master associated with the computer showed that this move 23:...Nd3 was in fact excellent because this position is curiously at the B advantage when one pushes the analyses which I followed with attention but which, for this reason, I could not note.

**24.Nb1! Bb2 25.Qd2 Nc2 **Karpov had planned 25...a5 26.a3! *(26.Qxb2? Rc2 27.Qa3 Rxa2–+) *26...Rc2 27.Qe1 Qb5 28.axb4 Re2 29.Qxe2 Qxe2 30.Rd2 which seems excellent for W's, but once again if we push the calculation we discover that after 30:...Qb5! 31:Rxb2 Qxb4 the White play will not be so easy.

26.Kh1 Qe7 27.Bg1 Nd7 28.Rf3 Qb4 29.Qh6 Qf8 30.Qg5 Qg7 31.Qd2 (31:f6 was seriously to be considered).

31...b6 32.Rdf1 a5 33.h4 Nb4 34.a3 Rc2 35.Qf4 Nc6 36.Bh3 Here again, we thought that 36:f6!? was interesting but the Master found the defence 36:...g5! 37:hxg Qg6

36...Nd8? 36:...b5! seemed necessary and perhaps allowed B to hold, based on the conviction that W has no winning attack... This debate has occupied us for some time but it seems to be true.

**37.Be3! **It is quite extraordinary that in this position, Karpov judges that the W win will be made on the queenside by exploiting the bad position of the black pieces! To do this, the R's must be exchanged twice by Rf2, and to do this, Be3 must first be played to maintain the d4 defence while preventing a subsequent Qh6.

Faced with an alien player who sees this while everyone else is looking for mate in force on the kingside, it is certain that the young prodigy of the time has something to occupy himself.

**37...b5 **[37...g5? 38.hxg5 Nxe5 39.Qxe5] **38.R3f2! b4 39.axb4 axb4 40.Rxc2 Rxc2 41.Rf2 Rxf2 42.Qxf2 Ba3 43.Qc2+- Nxe5 44.dxe5 Qxe5 45.Qc8! Qe4+ **[45...Qxe3 46.Qxd8+ Kg7 47.f6+ Kh6 48.Qf8#]

**46.Bg2 Qxb1+ 47.Kh2 Bb2 48.Qxd8+ Kg7 49.f6+ Bxf6 50.Bh6+ Kxh6 51.Qxf6 Qc2 **it's completely over, but you have to stay focused because 52:Kg3?? threatening g5+ and Bf3# would allow 52:..Qc3+ while 52:g5+ Kh5 53:Kh3? would allow Qf5+

**52.g5+ Kh5 53.Kg3! **now, Qc3+ would be faced with Bf3 check! **53...Qc7+ 54.Kh3 1–0**

**Finally, there was the fairytale session at the dinner table.**

For once I won't report the whole problems because the first problem presented a Take&Make with Nightriders, which has already been explained last time and therefore rather nice, but in a twin selfmate helped, and I don't like hs and if I liked one solution, the twin didn't seduce me.

Then, the second problem was more fun, but in my opinion much too difficult to find and I don't see what to explain to help find the solution. So I'll just give it, and show why it's a solution, which should be more interesting to curious readers.

**Problem 1.**

hs#2,5. Twin** : Na4 on b4**.

Take&Make

NIb1 and NId5: Nightriders.

I remind what I have already explained in the report of the April 15 session.

** Take&Make: The pieces normally make the moves without capture. On the other hand, when a piece captures it must imperatively (to finish its move) make a move according to the movement of the captured piece. A capture is only possible if the associated move is possible.

** Nightrider (noted NI): This is a piece that plays as many moves of N as it wants, but all the steps must be in exactly the same direction. For example, the NId5 can play f6, h7 but not g8 because the 2 steps to get there are not identical.

** I skip the self helpmate, which for me is almost always a sign of impotence: the author has a selfmate one move position, but he is unable to make it into a worthwhile selfmate n move, so he gives another starting position and says that one must first play as in a helpmate to reach this mysterious position which will be a selfmate one move. Obviously, this becomes much harder to find, especially in Take&Make where the possibilities in helped are multiplied.

To sum up: both sides cooperate (assisted) in a first step to reach a position which is a selfmate one move.

Add a comment