The Grey Labyrinth is a collection of puzzles, riddles, mind games, paradoxes and other intellectually challenging diversions. Related topics: puzzle games, logic puzzles, lateral thinking puzzles, philosophy, mind benders, brain teasers, word problems, conundrums, 3d puzzles, spatial reasoning, intelligence tests, mathematical diversions, paradoxes, physics problems, reasoning, math, science.

borschevsky · Chessnut

For the first one, I think 1. Ba7+ and 2. b6 followed by putting the white king on h1 should do it.

THUDandBLUNDER · Threefold Repetition

borschevsky · Chessnut

Not right away, but then white will place his K on f1 and B on b8, like: 1.Ba7+ Kc7 2. b6+ Kd8 3.Kc1 Bxg4 4.Kd1 Ke7 5.Ke1 Rg8 6.Kf1 Be6 7.Bb8. If black takes the B, then the K gets to h1; if not, white just plays the B along f4-c7 and black can't make progress.

Laramie · Daedalian Member

#2: partial solution, I think

1. Nb5, threatening Pa8+ if black moves the Queen off the 8th rank. Black cannot put white in check (except for 1. ... Qd4+, for which white would respond NxQ). So, if black does not move the queen from the 8th rank, 2. Kxp, and so on. There are a lot of possibilities to consider at that point.

Zag · Unintentionally offensive old coot

I toyed with that and discarded it. Here's why: 1. It's the obvious move. These things are never the obvious move. 2. As black, below is my response. I think we can agree that if I ever get your passed pawn with my queen intact, I will win.

1. Nb5 Kb6
2. Kxe2 Qc8
3. if N moves, Qa8, then 4. Nb5, Qb7
3. if K moves, Qb7
4. K moves, Be7
5. K moves, Bd8
6. K moves, Bc7
7. if NxB, Qxa7
7. if K moves, Bb8
8. whatever happens, I've got the pawn and still have my queen.

Laramie · Daedalian Member

Actually, #1 was the obvious move, so this one might be too.

I'll take a look at your logic....

borschevsky · Chessnut

Yeah, I don't see any way to draw for white. Black can play Bd6-c7-b6 and Kb7 to take the a7 pawn, and then just attack with the queen.

Laramie · Daedalian Member

Well, if not 1. Nb5, black can seemingly force 2. Nb5 with 1 ... Kb7.

As I see it, there are three main possibilities.

1. White sacrifices the knight and the pawn at a7, and then "hides" the king at h3 or d3 and somehow forces a stalemate. For example, if the white king was at h3 and black moved the Queen to d2, we would have a stalemate. But, I don't see any way to make this work.
2. White promotes the pawn and puts black in perpetual check. Again, I don't see any way to make this work.
3. White effectively pins the black queen on the eighth rank by threatening Pa8. Zag's post is compelling, though, and I don't see a way around that.

Any other possibilities?

borschevsky · Chessnut

couple more possibilities:
- white trades his knight for the black queen somehow (I don't see how)
- white sets up some kind of entry blockade. For ex, put the knight on c2 and the king on e2; there's no way for the black queen to enter on the d file. But it doesn't matter, the queen can enter on the h file, or black can just wait and white has to move the N or K.

THUDandBLUNDER · Threefold Repetition

knightshade · Daedalian Member

Yeah. I usually suck hardcore at chess, but I think I can get #2.
The king takes the pawn at e2 and sits there. Now black must take the pawn at a7 before it promotes. Also, it has to open up white's defense by killing a pawn at b3 or f3, the only unprotected pawns. In the meanwhile, white's knight moves to b1 and then to d2, protecting both pawns at b3 and f3. With the knight at d2, white's king can 'circle' around that knight, protecting it from being taken and leaving the game in an unwinnable state for both sides.

I think that's it. I'm sure someone can make this more rigorous than I....

Pfft...

-k

Zag · Unintentionally offensive old coot

borschevsky · Chessnut

Yep, I think knightshade's idea works: 1. a8Q+ Qxa8 2. Nb1 Qd8 3. Kxe2 and 4. Nd2 is a draw.

Laramie · Daedalian Member

Nicely done, knightshade.

THUDandBLUNDER · Threefold Repetition

White has got himself into another fine mess.
How did he escape this time?

Laramie · Daedalian Member

A few thoughts....

White can draw by

1) ... getting the knight to h2 or d2 before black promotes.
2) ... safely promoting a pawn of his own
3) ... capturing black's knight and h7 pawn without losing the knight or bishop (as I recall, bishop-knight vs. queen is a draw, right?)
4) ... putting black in perpetual check

#4 seems highly unlikely, but so do the others...

THUDandBLUNDER · Threefold Repetition

kevinatilusa · Daedalian Member

Another way that I can't see how to make work would be to trap black's king in the corner in such a way that none of your own pieces in that corner can move, or so that the bishop can safely move while maintaining the lock (you need some way to avoid black trapping your king in the corner of the board and forcing you to break up the formation).

Laramie · Daedalian Member

That's a good idea. Take the black knight and then use your remaining pieces to both protect each other and trap the king. You can force a capture of the black knight with 1. Pg7 NxP (forced), but I haven't been able to get it to work after that.

Tony Gardner · Daedalian Member

kevinatilusa* · Guest

If 1. ...Kg8

2. Ng4 threatens both Nxf2 and Ng6#

kevinatilusa* · Guest

actually, isn't that double threat available after Nxg7 too?

kevinatilusa · Daedalian Member

(now logged in so I can edit away embarrassments like the last two posts).

In the first case, black can capture the knight at g6, and in the 2nd the king is on h8 and not g8.

Tony Gardner · Daedalian Member

kevinatilusa · Daedalian Member

Don't think Nf6 is mate. However,

1. g7+ Kg8
2. ng4 f1=Q
3. nf6+ Kf7
4. f8=Q#

seems to force the knight capture

Tony Gardner · Daedalian Member

yeah sorry about that i confused the check sign (+) with the mate sign (#)

Coyote · Posted: Fri Apr 01, 2005 8:45 am Post subject: 29

Tony Gardner · Daedalian Member

I think black would simply play 4. ... Qxf7+ after which it's all over

Coyote · Posted: Fri Apr 01, 2005 9:00 am Post subject: 31

Sorry, I left out a move:
1.g7 Nxg7
2.Nf7+ Kg8
3.Bc5 f1Q
4.Nh6+ Kh8
5.Ba3

Tony Gardner · Daedalian Member

yeah at first glance i can't find a way for to black to win. nice one coyote

Laramie · Daedalian Member

What about 5. ... Qf2+ followed by 6. ...Qxf5 ? If the pawn at f5 is not protected, I don't see how that can be a draw.

Tony Gardner · Daedalian Member

you mean Qg2+ followed by Qxg5? in that case white plays Nf7+ winning the queen

THUDandBLUNDER · Threefold Repetition

Tony Gardner · Daedalian Member

okay, back to the drawing table...

Guest · Posted: Fri Apr 01, 2005 6:47 pm Post subject: 37

Sorry, but I'm still not understanding #1. Was borchevsky's move list of 1.Ba7+ Kc7 2. b6+ Kd8 3.Kc1 Bxg4 4.Kd1 Ke7 5.Ke1 Rg8 6.Kf1 Be6 7.Bb8 correct?

If so, or if it did start 1.Ba7+, why wouldn't the next part be RxB or KxB???

Tony Gardner · Daedalian Member

borchevsky' solution as in posts 2 and 4 does the job. if the bishop is taken by black after 1. Ba7+ , then the white king can reach h1 in time and a draw is realised (nowhere for the rook to enter, Rg2 would be a stalemate).

Laramie · Daedalian Member

In the interests of collaborative solving, a few thoughts:

Coyote's approach is promising, but I feel like white has to take black's knight to make it work.

Another line that seems to have some promise is 1. Nf7+ .... 2. g6Xh7, forcing 2. .... Kxh7.

The only moves that seem to have any real possibilities are

1. g7+
1. Nf7+
1. Bc5
1. Bh6
1. Ng4

Unfortunately, none of them seem to quite do it.

Laramie · Daedalian Member

Also, I think the real trick here is to somehow manage to take black's knight without losing white's knight or bishop. If you can do that, there are numerous ways to trap the king in the corner.