Friday, December 15, 2017

For daily use


  1. ehhh... a little off topics

    The relationship between cognitive ability and chess skill:
    A comprehensive meta-analysis

  2. FEN: 1r1q1rk1/p2bppbp/3p1np1/4n3/3NP1P1/2N1BP2/PPPQ3P/1K1R1B1R b - - 0 1

    Zhuravliov-Koskin, USSR 1963 (Unable to find the game score in a database)

    I am continuing to work on the scheme outlined above, in the context of solving problems from the excellent book Fundamental Checkmates, Antonio Gude. See page 94 for this position.

    When I looked at the position, something struck me as an insight based on the outlined procedure given above. When we look at PoPs and LoAs, often times we "see" B.A.D. pieces. However, we often don't extend that knowledge to include other pieces that may be masked (sometimes obscured beyond reasonable pattern recognition).

    In the given position, I immediately noticed that the Black Rook at b8 "attacks" the White Pawn at b2, which in turn is "defended" by the White King at b1. So, the b2 square is B.A.D. However, when I "looked" again, I "saw" that the Black Bishop on g7 is also "attacking" b2 - albeit through the two Black Knights (on f6 and e5) and one of the White Knights (on c3). Given the potential "superiority" on b2, it then triggered a look to "see" if the Black Bishop and Black Rook can "combine" in the "attack on b2. Using Capablanca's idea of just shifting the appropriate pieces as needed without the usual calculation of moves, it became "obvious" (on some level) that the two Black Knights and the White Knight COULD be "moved" via threats.

    The first threat is a capture on f3 with 1. ... Nxf3! This threatens White's Queen on d2, so it seems "obvious" to recapture: 2. Nxf3. Black follows up with 2. ... Nxe4. White responds with 3. Nxe4 and miraculously, the line of the Black Bishop on g7 is now cleared.

    Another background consideration is the idea that Black can sacrifice the Black Rook on b8 and immediately "reload" the same effect with the Black Queen. So, 3. ... Rxb2! Taking the Rook with 4. Kxb2 allows the Black Queen to come into play with tempo (check), so White tries to sidestep into at least temporary safety with 4. Kc1. But Black can force the King back into the line of fire with 4. ... Rb1+! 5. Kxb1. Black then brings the Queen into play with check 5. ... Qb8+ and White is mated after .

    My point is NOT about solving this particular problem but gives an example of how efficacious the idea is of extending the "line of attack" from each line-moving piece across the board, REGARDLESS OF OBSTACLES IN THE LINE OF ATTACK in the current position.

    I'm making progress with this "visualization" idea, because it popped into "sight" as soon as I looked at the position.

  3. I often get an "itch" when I take the "obvious" road when analyzing. In the analysis above, that occurred after this statement:

    "The first threat is a capture on f3 with 1. ... Nxf3! This threatens White's Queen on d2, so it seems "obvious" to recapture: 2. Nxf3." Is there an alternative to helping Black force mate? Where there is life, there is always hope!

    So, I loaded up GM Stockfish and left him to analyze over night. He did not make the "obvious" move 2. Nxf3. What a surprise - NOT.

    New game
    1r1q1rk1/p2bppbp/3p1np1/4n3/3NP1P1/2N1BP2/PPPQ3P/1K1R1B1R b - - 0 1

    Analysis by Stockfish DD 64 SSE4.2:

    1. -+ (-2.22): 1...Nxf3 2.Qf2 Bxg4 3.Nb3 Ne5 4.Rd4 Rc8 5.h3 Bf3 6.Bg2 Bxg2 7.Qxg2 Nc4 8.Rd3 Nxe3 9.Rxe3 Nd7 10.Qg3 Qc7 11.Rf1 e6 12.h4 Ne5 13.Ka1 Qb7 14.Qf4 f5 15.Ree1 fxe4
    2. = (0.00): 1...Rxb2+ 2.Kxb2 Nxf3 3.Qd3 Ne5 4.Qd2 Nf3
    3. +/= (0.56): 1...h5 2.g5 Nxf3 3.Qf2 Qa5 4.Nb3 Rxb3 5.axb3 Nxg5 6.Qe1 Nf3 7.Qe2 Ne5 8.h3 Rb8 9.Rd4 Bc6 10.Bg2 Rb6 11.Na4 Rb7 12.Bd2 Qc7 13.Nc3 Bd7 14.Rd1 Qc5 15.Be3 Qc7 16.R1d2 Kf8 17.Nd5
    4. +/- (0.80): 1...Qc7 2.Be2 Rfc8 3.Nb3 Be6 4.h4 h5 5.g5 Nfd7 6.Bd4 a5 7.f4 Nc4 8.Bxc4 Bxd4 9.Qxd4 Bxc4 10.Rh2 Rb4 11.a3 Rb7 12.f5 Ne5 13.Nd2 Bd3 14.cxd3 Qxc3 15.Qxc3 Rxc3 16.fxg6
    5. +/- (0.82): 1...Qb6 2.b3 Qb7 3.Be2 Rfc8 4.h4 Qb4 5.Nd5 Nxd5 6.exd5 Qb7 7.h5 Qxd5 8.hxg6 hxg6 9.Ba6 Nc4 10.Bxc4 Qxc4 11.Qh2 e5 12.Qh7+ Kf8 13.Bh6 Bxh6 14.Qxh6+ Ke8 15.Qg5 Be6 16.Rh8+ Kd7 17.Rxc8 Qxc8 18.Nxe6 Kxe6 19.Qd2
    6. +/- (0.94): 1...d5 2.b3 dxe4 3.g5 Nh5 4.Nxe4 a5 5.Qe1 Qc7 6.Qc3 Rfc8 7.Qxc7 Rxc7 8.Ba6 a4 9.Rhe1 Nc4 10.Bc1 axb3 11.axb3 Ne5 12.Be3 Ra8 13.Be2 Nc6
    7. +/- (1.03): 1...Qc8 2.Be2 Qb7 3.b3 Rfc8 4.h4 Qb4 5.Nd5 Nxd5 6.exd5 Qb7 7.h5 Qxd5 8.hxg6 hxg6 9.Ba6 Nc4 10.Bxc4 Qxc4 11.Qh2 e5 12.Qh7+ Kf8 13.Bh6 Bxh6 14.Qxh6+ Ke8 15.Qg5 Be6 16.Rh8+ Kd7 17.Rxc8 Qxc8 18.Nxe6 Kxe6 19.Qd2
    8. +/- (1.11): 1...a5 2.Be2 a4 3.h4 Qc8 4.h5 Nc4 5.Bxc4 Qxc4 6.a3 Rfc8 7.Ka1 d5 8.hxg6 hxg6 9.g5
    9. +/- (1.17): 1...Be6 2.Be2 Qc8 3.h4 Bc4 4.Ka1 Qb7 5.Nb3 Qa6 6.Bxc4 Nxc4 7.Qe2 Nd7 8.Bd4 Bxd4 9.Rxd4 Rfc8 10.Nd5 Kf8 11.Ne3 Rb4 12.Nxc4 Ra4 13.h5 g5 14.a3 Ne5 15.Nbd2 Nxc4 16.Nxc4
    10. +/- (1.37): 1...Rb4 2.Be2 Qb8 3.Nb3 Be6 4.Nd5 Bxd5 5.exd5 Rc8 6.h4 h5 7.g5 Ne8 8.c3 Nc4 9.Bxc4 Rbxc4 10.Bd4 Bxd4 11.Nxd4 Rxc3 12.Nc6 R8xc6 13.dxc6 Rxc6 14.Rhe1 e6 15.Rc1 Rxc1+ 16.Rxc1
    11. +- (1.49): 1...Re8 2.Be2 Qc7 3.Nb3 Qb7 4.g5 Nh5 5.Bd4 a5 6.Nd5 Nc6 7.Bxg7 Nxg7 8.a4 Ne6 9.Bb5 Nc7 10.c4 Qa7 11.Nd4 Nxd4 12.Qxd4 Qxd4 13.Rxd4 Ne6 14.Bxd7 Nxd4 15.Bxe8 Rxe8 16.f4 Kg7 17.Rd1 Nf3

    (Coble, Asheboro, NC 10.02.2018)

    Black still has a significant (winning?) advantage, but White is still playing, which is an important factor when playing against flesh and blood. This illustrates an important principle: make it as hard for your opponent as possible; don't just throw in the towel and make moves that allow the opponent to get what he wants. Or, in the immortal words of GM Tartakower:

    "The mistakes are there, waiting to be made. No one ever won a game by resigning."

  4. GM Stockfish is now Super Super Super GM Stockfish 9 with new improved Elo..

  5. @ Aox:

    Thanks for the update notice. I downloaded Stockfish 9 x64 (1 CPU) version and installed it into my Fritz 11 program. Might as well have a 3391 Elo engine analyzing instead of Fritz 11 at 2853 Elo. In reality, it doesn't make any difference whatsoever WRT to MY playing skill: a 2853 GM can bust me just as easily as a 3391 GM.

  6. its not only about strength.. its about speed. engines gain ~~~40 elos by doubling the time for the calculation.
    So if you analyse your game with fritz and give the engine say 100 sec per move it would be better to give stockfish 1 sec for each move to get informations of better quality.
    I analyse every game i play with an engine and modify my opening repertoir according to this. Additionaly i use my errors for my spaced repetition trainingsset. With a strong engine its ok to give it 1 sec per move.. i dont have to wait to play my next game.

  7. doing some Ct-art level 20-30 problems and thinking specifically about pins.So I am looking at this search . Thinking out loud there are pins where you pileup on, pinned pieces where mate occur on the pinned piece , pins where the pin piece can perform a function such as protect a piece or cant move to block a check, or pinned piece negatively blockades the power (LOA,movement protection ) of a piece behind it. There are also a pin tactics where a piece is decoyed to a position so a pin can be created. So with pins you pile up on, you dance on the head of them , or you create them.

  8. A pin is generally considered to be a tactical element. Yet Nimzovich considered a pin to be one of the elements of his "system" of strategy.

    My System, 7. The Pin: "After the difficult sixth chapter [6. The Elements of End Game Strategy], difficult at any rate in the positional sense, the present one may appear very easy. And the question may perhaps be asked, whether the pinned piece can really be spoken of as an element in our sense, since a game may be laid out on the basis of an open file or a passed Pawn, but surely never of a pin! This point of view we cannot share. True, pins as a rule occur in purely tactical moments as, for instance, in the pursuit of the fleeing enemy; on the other hand, however, a pin foreseen in the planning of a game may quite logically influence its whole course.

    In another context [2. On Open Files], Nimzovich discusses the "evolutionary" and the "revolutionary" attacks. The "evolutionary" attack concerns the concentration of force against one point, in order eventually to get superior forces to bear on it or through thinning the pin defenders' ranks by exchange. The "revolutionary" attack dispenses with a slow buildup of pressure against a point, relying instead on sacrifices and tactics to gain an objective.

    Nimzovich prescribes the approach to be taken: "In what chronological order are these two methods of attack to be employed? The answer is this:—First try the converging attack, i.e., attack the obstructing Pawn with several pieces; by doing so opportunity may be fond to force the defending pieces into uncomfortable positions where they will get into one another's way: for the defense will often be cramped for space. Afterwards, see whether among other things there is a possibility of a break through by force, in other words of a revolutionary attack.

    A pin that persists over several moves with increasing pressure on the pinned piece (with possible thinning of the defenders' ranks) exemplifies the evolutionary attack (strategy), whereas the tactical utilization of a pin exemplifies the revolutionary attack (tactics). At least, that's my understanding of the difference.

    I really like your summary: "So with pins you pile up on, you dance on the head of them, or you create them." It's succinct and thus easy to remember, like Temposchlucker's PoPLoAFun formulation.