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  1. #1
    Monster of the deep Kevin Bonham's Avatar
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    Syzygy (7 piece) tablebase site online

    Looking for a 6-piece tablebase site I found there is now a 7-piece one online.

    https://syzygy-tables.info/

    Instead of always giving an immediate distance to mate it gives "DTZ", which is distance to zero (shortest number of half-moves to reset the 50-move draw count). Sometimes it gives DTM as well.

    It also gives the longest wins and losses for material balance, including a "frustrated" category which I assume means frustrated by the 50 move count.

    For instance for KBNP vs KNP this position is a forced win but with best play by both sides in terms of the 50 move rule, white takes black's knight on the 100th half-move, meaning that black never gets to claim the draw.

    FEN Viewer

  2. #2
    Monster of the deep Kevin Bonham's Avatar
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    An example of the kind of things one can find:

    FEN Viewer


    White Black to move is a piece up down but because of poor king and passive piece position Black has a forced win with DTZ 25.
    Last edited by Kevin Bonham; 13-01-2020 at 12:35 PM.

  3. #3
    CC Grandmaster Desmond's Avatar
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    Quote Originally Posted by Kevin Bonham View Post
    An example of the kind of things one can find:

    FEN Viewer


    White to move is a piece up but because of poor king and passive piece position Black has a forced win with DTZ 25.
    Hmm is it black to move? White to move Bb6+ looks good enough
    So what's your excuse? To run like the devil's chasing you.

    See you in another life, brotha.

  4. #4
    Monster of the deep Kevin Bonham's Avatar
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    Quote Originally Posted by Desmond View Post
    Hmm is it black to move? White to move Bb6+ looks good enough
    Yes it's black to move (fixed).

  5. #5
    Monster of the deep Kevin Bonham's Avatar
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    An unnatural but startling position:

    FEN Viewer


    Black to move. Although white seems to be winning queen for rook with a draw by force, this is actually a win for black. How?

  6. #6
    CC Grandmaster Capablanca-Fan's Avatar
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    Quote Originally Posted by Kevin Bonham View Post
    An unnatural but startling position:

    FEN Viewer


    Black to move. Although white seems to be winning queen for rook with a draw by force, this is actually a win for black. How?
    Probably way beyond most humans who haven't seen the solution. According to the tablebase, 1... Kh7 is the only move to win but it's "frustrated" because DTZ = 78. White's best resistance is 2.R8a7 pinning the Q. The gist of Black's winning method is to unpin that Q by placing the other Q on the same rank. White's best resistance is to try to keep the K close to the Rs. But Black's series of checks forces a position where the WK is in check on the c-file with Qs on b7 and c7. The Qb7 is now free to move, and checks. Eventually the same structure will be repeated with K on d-file, Qs on c7 and d7. Now the Qc7, first the unpinning Q now becomes the unpinned Q and checks. The Qs take turn to check so they are next to each other, with the position moving one file right, then repeated. So we reach the Kg1 faced by Qs on f7 and g7. Now the K must retreat to the h-file, whereupon a check by the Qf7 forces mate quickly, e.g. Kh2 Qf2+, Kh3 Qg3#.
    “The history of the 20th century is full of examples of countries that set out to redistribute wealth and ended up redistributing poverty.”
    “There’s no point blaming the tragedies of socialism on the flaws or corruption of particular leaders. Any system which allows some people to exercise unbridled power over others is an open invitation to abuse, whether that system is called slavery or socialism or something else.”—Thomas Sowell

  7. #7
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    Quote Originally Posted by Capablanca-Fan View Post
    Probably way beyond most humans who haven't seen the solution. According to the tablebase, 1... Kh7 is the only move to win but it's "frustrated" because DTZ = 78. White's best resistance is 2.R8a7 pinning the Q. The gist of Black's winning method is to unpin that Q by placing the other Q on the same rank. White's best resistance is to try to keep the K close to the Rs. But Black's series of checks forces a position where the WK is in check on the c-file with Qs on b7 and c7. The Qb7 is now free to move, and checks. Eventually the same structure will be repeated with K on d-file, Qs on c7 and d7. Now the Qc7, first the unpinning Q now becomes the unpinned Q and checks. The Qs take turn to check so they are next to each other, with the position moving one file right, then repeated. So we reach the Kg1 faced by Qs on f7 and g7. Now the K must retreat to the h-file, whereupon a check by the Qf7 forces mate quickly, e.g. Kh2 Qf2+, Kh3 Qg3#.
    Amazing - the winning move is a self-pin! But it makes sense - taking the rook obviously won't win, as White can cut the king off, forcing the draw.

  8. #8
    CC Grandmaster Capablanca-Fan's Avatar
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    Sorry, this is not frustrated because DTZ = 78 refers to half moves, just as KB had explained.
    “The history of the 20th century is full of examples of countries that set out to redistribute wealth and ended up redistributing poverty.”
    “There’s no point blaming the tragedies of socialism on the flaws or corruption of particular leaders. Any system which allows some people to exercise unbridled power over others is an open invitation to abuse, whether that system is called slavery or socialism or something else.”—Thomas Sowell

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