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Posers and Puzzles

Posers and Puzzles

  1. Standard member SwissGambit
    Caninus Interruptus
    03 Nov '07 07:51

    Minimum number of Knight moves?
  2. Standard member celticcountry
    Copyright ©2001-2006
    03 Nov '07 09:56
    Five?

    Am I missing something here?
  3. Standard member SwissGambit
    Caninus Interruptus
    03 Nov '07 17:43 / 1 edit
    Originally posted by celticcountry
    Five?

    Am I missing something here?
    I'm asking for the minimum number of Knight moves that must have been played to reach this position, not the number of Knight moves White currently has.
  4. Standard member Peakite
    Sais
    03 Nov '07 23:06
    First glance it didn't seem to tricky. There can't be any promoted men. Only the f7 pawn has been taken, but that must have been captured there.

    White needs 7 captures (2N, 2R, Q, wB and fP)
    Black can only make two (R and Q). These must be d7xe6 and axb(not yet sure what.

    Looks as though the f1 and f8 bishops must be firstly captured by Ns too, adding to a basic 12 moves for Ns just to reach their final positions if a direct route can be taken.

    Problem is that to unblock e6 the B on c8 must be replaced. Only two uncaptures possible for white prior to this, on c6 and d6. Therefore the latter must be the B. It would be easy if two rooks can be uncaptured as I'd want to get both through c8 before the B returns.
  5. 04 Nov '07 10:10
    15 i think
  6. Standard member SwissGambit
    Caninus Interruptus
    04 Nov '07 21:19
    Originally posted by gsxr1000
    15 i think
    Let's see a proof game, or retraction of moves that shows it.
  7. Standard member Peakite
    Sais
    06 Nov '07 21:13


    Right, I've retracted back to this position. I'll give the moves a little later, but as white's uncaptures will give black two pieces (R & Q) which are free to waste a move, alongside the wR, the Ns can go about their business.

    Both f bishops must be captured upon their starting squares by knights, though in no case do I have to worry about putting the K in check upon approach. And both capturing Ns can move onto their finishing squares without interrupting other crucial play.

    Only problem with this is that whites last uncapture (a2xb3) will close his position so must move Ns in order to allow black to retreat the final few moves as quickly as possible.
  8. Standard member Peakite
    Sais
    06 Nov '07 21:25 / 1 edit
    And conveniently I can make the basic N moves which don't block the position whilst black takes back the final three N moves.


    From here white uncaptures to leave a black N on b3, three moves back for each side.

    This can be reached as the black c or a pawn can be left on the fourth rank after my retractions (to follow) in the first instance. Plently of opportunity to waste time still available.

    Therefore total moves:

    bN b8-c6-d4-b3 (3 moves)
    bN g8-f6-g4-e3xf1-e3-d5 (6 moves)
    wN b1-c3-a4 (2 moves)
    wN g1-h3-f4-g6xf8-e6-c7-a8 (7 moves)

    Total of 18 moves then.

    Edit: I can't go via e6 and c7 as I'd check the K on the way. e6-f5-e6 would solve the problem with two extra moves (to make 20)

    It is possible for the N to move from f8 to a4 and the other from b2 to a8 but these both take the same number of moves.

    My answer is twenty, not 18.
  9. Standard member Peakite
    Sais
    06 Nov '07 21:47



    From here to reach the position in the problem.

    1. dxe6 Rg8
    2. exf7 Rf8
    3. Re6 dxe6
    4. Kf1 Bd7
    5. Kg1 Bb5
    6. Kf1 Bd3
    7. cxd3 Rc8
    8. Qb3 c4
    9. Rd1 c3
    10. Ke1 c2
    11. Qb4 Rc3
    12. bxc3 axb4
    13. Ba3 b3
    14. Ra1 b2
    15. Ra2
  10. Standard member SwissGambit
    Caninus Interruptus
    06 Nov '07 22:24
    Originally posted by Peakite
    And conveniently I can make the basic N moves which don't block the position whilst black takes back the final three N moves.

    [fen]r1bqkbnr/pppppppp/8/8/N7/1P5N/1PPPPPPP/R1BQKB1R w KQkq[/fen]
    From here white uncaptures to leave a black N on b3, three moves back for each side.

    This can be reached as the black c or a pawn can be left on the fourth rank ...[text shortened]... r from b2 to a8 but these both take the same number of moves.

    My answer is twenty, not 18.
    Correct. Good spot on the Nc7+ issue.
  11. Standard member afx
    14 Nov '07 13:04
    Just 2!
    Kc3 and Ka4
    The Knight on a8 could be a converted pawn
  12. Standard member HurricaneConway125
    SUPREMO OF SOMERSET
    14 Nov '07 16:43
    Originally posted by afx
    Just 2!
    Kc3 and Ka4
    The Knight on a8 could be a converted pawn
    it clearly isn't seeing as white's A pawn has been doubled onto the B-file so a pawn can't therefore make it to A8
  13. Subscriber sonhouse
    Fast and Curious
    14 Nov '07 18:14
    Originally posted by SwissGambit
    [fen]N6k/1p2pPpp/4p3/8/N7/B1PP4/RppPPPPP/4K3[/fen]
    Minimum number of Knight moves?
    Just out of curiosity, are you ever going to actually play a game? I see you have been here since april and have a grand total of zero games played.
  14. Standard member SwissGambit
    Caninus Interruptus
    15 Nov '07 06:04
    Originally posted by sonhouse
    Just out of curiosity, are you ever going to actually play a game? I see you have been here since april and have a grand total of zero games played.
    I've had so many people ask this now that I don't dare ruin the mystique by answering the question.
  15. 15 Nov '07 08:18
    Originally posted by SwissGambit
    I've had so many people ask this now that I don't dare ruin the mystique by answering the question.
    Out of curiosity, do you have a fide title?