Please turn on javascript in your browser to play chess.
Posers and Puzzles

Posers and Puzzles

  1. Standard member SwissGambit
    Caninus Interruptus
    07 May '07 18:06 / 1 edit
    SwissGambit, Original

    Add both Kings, 5 white pawns and 3 black pawns to create an Illegal Cluster.

    Illegal Cluster: An illegal position that becomes legal if any piece is removed from the board (besides the Kings, obviously).
  2. 07 May '07 20:59
    Solution sent!
  3. 08 May '07 04:36
    Solution retracted...
  4. 08 May '07 15:30
    Solution resent!
  5. Standard member SwissGambit
    Caninus Interruptus
    08 May '07 17:29
    Originally posted by Jirakon
    Solution resent!
    Looks like that one will have to be retracted, too. [Please keep at it though - thorough testing is needed to ensure the problem is sound...]
  6. 08 May '07 18:14
    Solution reretracted...
  7. Standard member SwissGambit
    Caninus Interruptus
    08 May '07 18:37 / 1 edit
    Originally posted by Jirakon
    Solution reretracted...
    I was able to modify your last solution slightly and make it work. The problem is cooked (multiple, unintended solutions). I will try and come up with a fixed version.

    Edit: Just got your PM and you got the same thing I did. Good work.
  8. Standard member SwissGambit
    Caninus Interruptus
    08 May '07 19:01 / 3 edits
    Here's Jirakon's cook:
    [fen]7k/pp1p1K1P/7r/7P/7P/7P/7P/B7[/fen]
    White pawns must have made at least 10 captures. Bc8 was captured at home, bringing the total to 11. White's last move was Kf6xBf7, preceeded by Bg6-f7+ (there is no other way to cancel the check from bRh6). This makes 12 white captures, which is one too many. (continued below)
    The position becomes legal upon removal of any unit:
    Removing Ba1 or Rh6 eliminates one of the "problem" checks, and White need not capture Bf7. Removing a wP reduces the number of White captures. Removing a bP provides an extra unit for White to capture.

    ---------------------------------------------------------------------------------

    Here's the new version of the problem. There is one less wP to place, so hopefully that takes care of "too many captures" cooks.

    SwissGambit, Original

    Add both Kings, 4 wP, 3 bP, 1 bR to create an Illegal Cluster.

    Illegal Cluster: An illegal position that becomes legal if any piece is removed from the board (besides the Kings).
  9. Standard member Dutch Defense
    Stealer of Souls
    08 May '07 20:44 / 1 edit


    Muhahaha!
  10. Standard member SwissGambit
    Caninus Interruptus
    08 May '07 21:31
    Originally posted by Dutch Defense

    Muhahaha!
  11. 08 May '07 22:42
    Before I attempt the new variation, I wanted to submit my new puzzle.

    Black 1



    White 9

    Place the two kings on the board to create a legal position, or prove that this position is illegal regardless of where the kings are.
  12. Standard member SwissGambit
    Caninus Interruptus
    08 May '07 23:30
    Originally posted by Jirakon
    Before I attempt the new variation, I wanted to submit my new puzzle.

    Black 1

    [fen]5Q2/Q7/1Q6/4Q3/7Q/2Q5/3Q4/6Q1 w - - 0 1[/fen]

    White 9

    Place the two kings on the board to create a legal position, or prove that this position is illegal regardless of where the kings are.
    There are several solutions.

    1) +bKc8, +wKc6(5,4). Retract -1.g7xf8Q+ etc.
    2) +bKb1, +wKb3(4,5). Retract -1.Qxg1+ etc.

    In fact, almost any square where bK is checked by only 2 Q works. Just block one check with wK, and have the other Q retract check (and uncapture something if needed to give Black something to move).
  13. 08 May '07 23:50
    Whoops... my mistake. I forgot to mention that no piece was captured on the last move.
  14. Standard member SwissGambit
    Caninus Interruptus
    09 May '07 00:52
    Originally posted by Jirakon
    Whoops... my mistake. I forgot to mention that no piece was captured on the last move.
    There are still 2 solutions:

    1) +wKe6, bKe8. -1.Qa3-f8+ Kf8-e8 -2.Q~a3+
    2) +wKf3, bKf1. -1.Qc5(d4)-g1+ Kg1-f1 -2.Ke3-f3+
  15. 09 May '07 05:09
    Ok, that one ended up worse than I expected (I actually had a thrid solution; see if you can find it). This puzzle started much differently. I guess in all my messing with it, it got cooked. Here's what it started as:

    Black 1



    White 9

    Again, the last move did not involve a capture. The puzzle is still to place the two kings on the board so that the position is legal, or else prove that the position is illegal regardless of the kings' positions.