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Coyote · Posted: Sun Dec 26, 2010 8:10 am Post subject: 1

Well, okay, it's not exactly a sliding-block puzzle, but you may find it reminiscent of one as you try to maneuver the various pieces around their tight quarters:

Zag · Tired of his old title

This puzzle has languished here for a bit, so I thought I would take a stab at it. The restriction that white can't even give check has me stymied.

You didn't say who moves first, so I assumed white.

1. Ka3 Kd2
2. Kb2 Kd1
3. Ra3 Kd2
4. Ra2 Kd1
5. Qa3 Kd2
6. Rb3 Kd1
7. Qa4 Kd2
8. R(a2)a3 Kd1
9. Kc3 Kc1

There, I've managed to get the black king out of the D column. Then he's trapped, of course, so this whole approach may be wrong, but I'll let someone else continue from here. I've gotten to here

Coyote · Posted: Thu Dec 30, 2010 10:24 pm Post subject: 3

Yes, White moves first. Sorry, I'd really meant to mention that.
I don't want to steer things in any particular direction, since there's always a chance someone may find a faster approach than mine. However, I'll say that, as a sub-goal, I found it easier moving the Black King up to d4 than moving him over to a1.

Zag, if you'd like to keep trying the latter approach, here's a suggestion: after the second moves of your sequence, try (spoiler)
moving a queen to a2 instead of a rook.

Zag · Tired of his old title

I was trying to keep the queens tucked up behind the others. Also, I realized that I am not trapped from here, I can go

10. Qb4 Kd1
11. Kd3 Kc1
12. Qd4 Kd1
13. Q(a) b4 Kc1
14. Kc4 Kc2

j_s* · Guest

I ve been working on this for the past two days (to which my husband's response as I spent hours playing with a quarter of the chess board, "I m not even going to ask what you are doing, because I know I won't be able to figure it out.") and I think working off Zag's start I have a solution. Its ridiculously long, but its solved. yay.

I ll post my results later, once I ve checked them.

Thanks for a fun puzzle, Chuck. Revenge most foul!

MatthewV · Daedalian Member :_

I have the agree with Coyote, my initial feeling was getting both the queens onto the bottom row would be good for progress. I like to position the pieces so that the action I seek is possible and the figure out how to get to that position.

I got the black king to D4 in 20 moves. (Q at A1,A2, R at C1, C2 and K at B2)

However, I haven't found a way to round the corner yet. I did come up with a method that moves the king to C4 but left white with no options.

Zag · Tired of his old title

20. Rd2 Kb1
21. Qc4 Ka1
22. Kb3 Kb1
23. Q(c)d3 Ka1
24. Kc3 Ka2

Coyote · Posted: Sun Jan 02, 2011 2:56 am Post subject: 8

It's very interesting to see the different strategies being used here. j_s, I'm looking forward to seeing your solution, however long it might be. Including a diagram at important mileposts, as in Zag's play-by-play account, would be great, or at least an occasional commentary on some particular sub-goal that's been reached. This is one of those puzzles where I find the journey to be far more fascinating than the goal.

By now anyone working on this puzzle has no doubt settled into their own personal system, so I think it's okay for me to give my own strategy at this point. Especially since, now that I try to put it into words, it sounds hopelessly awkward--but then, I never have had the knack for finding the easiest approach to problems. Anyway, here it is:

First I found a way to reach a position that could be 'flopped' across the horizontal axis. If that's not clear, consider this position, that can be reached after Black's eighth move:

j_s* · Guest

So satisfying; I decided to start over and got it in 42 moves, which I m pleased with. I just checked it so it should be good (but please feel free to double check. I did find one mistake that was easy to fix (thankfully!))

(also I still have no idea how to draw the chess boards here, so I wont add that).

My solution (spoilered)

1. Ka3, Kd2
2. Kb2, Kd1
3. Kb1, Kd2
4. Qa4, Kd1
5. Qa1, Kd2
6. Q(c4)a4, Kd1
7. Rc4, Kd2
8.R(b3)b4, Kd3
9. Kb2, Kd2
10. Rc4, Kd3
11. Q(a1)a2, Kd2
12. Ra1, Kd3
13. Ka3, Kc3
14. R(b4)b1, Kd3
15. Kb4, Kd4
16. Rc1, Kd3
17. Rc2, Kd4
18. Qb1, Kd3
19. Q(a4)a2, Kd4
20. Kb3, Kd3
21. Qc1, Kd4
22. Qa3, Kd3
23. Rb1, Kd4
24. R(c2)b2, Kd3
25. Qa1, Kd4
26. Kc2, Kc4
27. Qa3, Kd4
28. Rb3, Kc4
29. Qa2, Kd4
30. Rb2, Kc4
31. Qa1, Kd4
32. Ra3, Kc4
33. Ra2, Kb4
34. Qd1, Kc4
35. Kb2, Kb4
36. Rd3, Kc4
37. R(a2)a3, Kb4
38. Kc2, Kc4
39. Q(a1)c1, Kb4
40. R(a3)c3, Ka4
41. Q(d1)d2, Kb4
42. Kd1, Ka4

Silverfire · Daedalian Member

I got 21 for the mini-puzzle, and yes, it's quite easy once you know what you're doing.

Lepton* · Guest

Yep, I get 21 as well. In case anyone shares my need to see a picture of that many knights, this is the state of the board after 5 moves.

Coyote · Posted: Wed Jan 12, 2011 12:32 am Post subject: 12

I think it's been long enough now that I can post my own solution. I won't bother spoilering this--anyone still working on the puzzle can simply not play through the moves shown.

1. Ka3, Kd2
2. Kb2, Kd1
3. Kb1, Kd2
4. Qa3, Kd1
5. Qa1, Kd2
6. cQa4, Kd1
7. Rc4, Kd2
8. bRb4, Kd3

This reaches the position shown in post #8. Interestingly, this is practically identical to j_s' first eight moves, but from here we go in wildly different directions:

9. Kb2 Kd2
10. Ka3 Kd3
11. Rb1 Kd2
12. cRc1 Kd3
13. Kb3 Kd2
14. 4Qa3 Kd3
15. Rb2 Kd4
16. cRc2 Kd3
17. Qc1 Kd4
18. Rb1 Kd3
19. Ra2 Kd4

lostdummy · Daedalian Member

Just returned after long time to check board, and found this great chess puzzle - not surprisingly from Coyote ;p

Anyway, after some work, I found solution with few less moves (28 moves):

1. Ka4-a3 Kd1-d2
2. Ka3-a2 Kd2-d1
3. Ka2-b2 Kd1-d2
4. Qb4-a4 Kd2-d1
5. Qa4-a2 Kd1-d2
6. Qc4-a4 Kd2-d1
7. Rc3-c4 Kd1-d2
8. Rb3-b4 Kd2-d3
9. Rc4-c1 Kd3-d2
10. Rc1-b1 Kd2-d3
11. Kb2-c1 Kd3-c3
12. Rb4-b2 Kc3-d3
13. Qa2-a1 Kd3-c3
14. Qa4-d1 Kc3-c4
15. Kc1-d2 Kc4-d4
16. Qa1-a3 Kd4-c4
17. Rb2-b3 Kc4-d4
18. Rb1-b2 Kd4-c4
19. Qa3-a1 Kc4-d4
20. Rb3-a3 Kd4-c4
21. Rb2-a2 Kc4-b4
22. Kd2-c2 Kb4-c4
23. Qa1-c1 Kc4-b4
24. Ra3-d3 Kb4-c4
25. Ra2-a3 Kc4-b4
26. Ra3-c3 Kb4-a4
27. Qd1-d2 Ka4-b4
28. Kc2-d1 Kb4-a4

as you can see, black king mostly repeat moves as white figures first free row 3 so he can move up, and then row 4, keep line C mostly free all time, free line B and then line A.

BTW, I noticed that comment about "now try it with bishops instead" and misunderstood that it was about this problem , replacing rooks with bishops - where obviously black king would be in check with two bishops, but I tried version of problem with only one bishop at C3 replacing white rook there, and I found solution ;p

So, potential bonus problem: replace in original setup Rook at c3 with Bishop (hint - it is easier than with two rooks ) .