Sunday, January 13, 2019

Looking for tasks to be automated

Broad: 
I focus on the following themes:
  • double attack
  • exposed king
  • defensive move
  • sacrifice
  • coercion
 Which make out 37% of the total problem set at Chess Tempo.

Deep:
  • Min rating: 1500
  • Max rating: 2000
Given the type of problems presented, it should be doable to solve every problem below 2000 in under 30 seconds.

I  have taken a peek at the higher rated problems. They are higher rated because there is more going on in the position. There are a lot of seemingly attractive lines which only distract you from the solution. It doesn't make sense to worry about problems with a higher rating than 2000, before you master everything thoroughly that is below 2000. Above 2000 it are the same themes, but there are more themes compacted within a single problem.

Themed exercises
Currently I do problems with a rating between 1780 and 1830. The common theme is fork/double attack. What I try to do is to recognize problems with the same characteristics. These characteristics aren't commonly known.

I suspect that these newly defined categories aren't limited to double attacks only. The themed problems make it easier to recognize the characteristics of such new category.

New category
A new category I recently discovered, are problems where the opponent takes a minor piece of you. In stead of taking back immediately, you start a duplo attack of your own, threatening a piece with a higher value.

White just played Nxe6 (taking the bishop). Black to move

4r3/kp3pB1/p2Rb1p1/4p2r/3N4/2R5/PPP2n1P/2K5 w - - 6 1
[solution]

White is a minor piece ahead. He has just captured the bishop on e6. In stead of taking back, you start a double attack of your own. Under what conditions is such action profitable?
  • The first condition is that one of your targets has a higher value than the piece that was just captured. 
 In the diagram above, you play 1. ... Ne4. The unprotected rook on d6 justifies the postponement of the take back on e6.
  • The second condition is that your target has to be unprotected
Additional: The net value of  one of your target (Rd6) minus the value of your attacker (Ne4) must be greater than the piece your opponent has taken (Be6), in case the target is protected. If both white rooks were protected, you basically exchange two minor pieces for a rook.
  • The third condition is that your opponent needs a tempo to get his high valued target into safety
You wasted a tempo to initiate a duplo attack. Now he must waste a tempo to save his target.
  • The fourth condition is that white has no double functional move at his deposal.
If white can save his knight on e6 AND can protect his rook at the same time, then your chances are gone.

Cluthering my Short Term Memory slots
This type of problems will typically overload my Short Term Memory slots. Taking stock of the values of the pieces while trying to remember in which branch of the tree I am will typically cause an administration shutdown. The problem will take ages to solve OR I go for the wrong solution.

If you take a close look at the problem, it is not exactly rocket science. The decisions to be made are simple and straightforward when you know what to look at.

By exploring these new categories, I hope to simplify my chess thinking. These counter threats aren't limited to double attacks only, of course.

4 comments:

  1. The themes:

    - double attack
    - exposed king
    - defensive move
    - sacrifice
    - coercion

    are not al just one pattern

    - defensive move
    - sacrifice
    are a big variety of patterns each
    and
    - exposed king
    is find all checks ;)

    Ne4 is not a double attack.. its a tripple attack, so after you take a rook, taking back the night can be punished by taking at e6

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  2. I do spaced repetiton of positions i have problems with since many years ( it did not help though ). The hope was to create new chunks this way. One problem of repetitions is that i often just think about the main line. This way i constrict my thinking and the view of the position. That might make the generated chunks of low value?
    Now i did add critical sidelines to my set of repetitions. Next will be to use these positions for boardvision exercises ( FAC, ..). I try to embed these positions deeper.

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  3. These chesstempo problems are funny. I spent 3:16 on it, but mostly in blunder-checking. RxN is obvious, so what move it not as obvious(?) Well, there's your answer then, the less obvious move. Anything slower than blitz, and one would probably find this tactic in a game.

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  4. I’m nearing the end of Victor Henkin’s excellent 1000 Checkmate Combinations, and worked out problem 448, Sikora-Chefranov, 1963 (sorry, can’t find the game).

    FEN: r2r1k2/pp1b1p2/4p3/q1b1P1RQ/8/3B4/PPP4P/2KR4 w - - 0 1

    I did not even consider GM Stockfish’s #1 variation!!

    Analysis by Stockfish 9 64:

    1. +- (#6): 1.Qxf7+ [I did NOT consider this move!!] Kxf7 2.Rf1+ Bf2 [Did NOT consider this move] 3.Rxf2+ Ke8 4.Rg8+ Ke7 5.Rg7+ Ke8 6.Bg6#

    2. +- (#7): 1.Qh8+ Ke7 2.Qf6+ Kf8 [Considered 2. … Ke8] 3.Rh5 Be3+ [Did NOT consider this move] 4.Kb1 Bh6 [Did NOT consider this move] 5.Rxh6 Qxa2+ [Did NOT consider this move] 6.Kxa2 Ke8 7.Rh8#

    3. +- (#7): 1.Qh6+ Ke7 2.Qf6+ Kf8 [Considered 2. … Ke8] 3.Rh5 Be3+ [Did NOT consider this move] 4.Kb1 Bh6 [Did NOT consider this move] 5.Rxh6 Qxa2+ [Did NOT consider this move] 6.Kxa2 Ke8 7.Rh8#

    4. +- (#19 – Ends up being 22 moves long after a long “think” by GM Stockfish!): 1.Rg6 Bc6 2.Rf6 Be8 3.Rxe6 Qd2+ 4.Kxd2 Rxd3+ 5.cxd3 fxe6 6.Qh7 Bh5 7.Qxh5 Kg8 8.Qg5+ Kf8 9.Rf1+ Ke8 10.Qg8+ Kd7 11.Rf7+ Kc6 12.Qxa8 Bb4+ 13.Ke2 Be7 14.Qc8+ Kd5 15.Rxe7 Kxe5 16.Qxe6+ Kf4 17.Qf6+ Kg4 18.Rg7+ Kh3 19.Qh6#

    I “learned” a couple of things from this problem:

    (1) At whatever step in the “thinking process” one considers CCT, ALWAYS consider sacrificing a Queen or Rook FIRST if there is any possibility of opening lines of attack against the opposing King, especially for heavy pieces.

    In this position, White has several lines of attack already open. All of Black’s pieces are “lost in space” over on the queenside. Two of White’s major pieces are already threatening the Black King, and both the WBd3 and the WRd1 have open lines to get at the King. Consequently, the position fits the criteria of the “3 piece” rule: If there are three pieces available for attacking a King, consider sacrificing one of them to open [more; critical] lines.

    (2) A lot can be gained from analyzing a problem, jotting down every “reasonable” line (i.e., all of the “candidate moves” and variations that were considered) and then putting the position up for analysis by a Grandmaster (in my case, GM Stockfish). I got the second and third of the top three “short” mates worked out to the end, but did NOT even look at any other alternatives, including the first and fourth place (in 22(!) moves) mates. (I wonder why not?!?) [Hence, my first “lesson learned – I hope” above.] As a result, there may be moves I haven’t considered somewhere within the sequence. In this position, I did not consider throwing the BBc5 on the wood pile to burn at f2, simply because it merely delays the inevitable rather than prevent it. It seems that chess programs consider ANY possibility that extends the horizon at which it is checkmated, no matter how hopeless that is to a human. It reminds me of this:

    NEVER GIVE UP!

    While there’s life, there’s hope!

    Aside: Shout out to Bryan Castro - an excellent article on his blog "How I Reached 2300+ on Chess.com Tactics Trainer"

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