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# A Christmas Chess Puzzle

#### Hemos posted more than 14 years ago | from the fun-with-the-mind dept.

281

Frederic Friedel writes "Here's a nice little chess puzzle I got from Grandmaster John Nunn many years ago. It looks incredibly simple, but even the strongest players in world have been stumped by it. The problem can be stated in one simple line: A game begins with 1.e4 and ends in the fifth move with knight takes rook mate. What are the moves? If you want to read a couple of stories on it, go to Chessbase. There is a very special prize to be won if you are able to solve it -- a book signed by some of the world's top chess players, testifying that the winner is The Greatest. "

Update: 12/25 11:50 by michael : Well, I thought I figured it out, but I was wrong.

1. e4&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;b8-c6
2. a4&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;b4
3. a1-a3&nbsp;&nbsp;c2
4. a3-d3&nbsp;&nbsp;b4
5. g7-e2&nbsp;&nbsp;d3++
-->

Just to clear up some confusion below, the condition is simply that a knight makes the last move of the game, which is a capture of a rook on move five (either color), and this results in checkmate for the other king. Either the knight or some other piece could be giving the check. One poster below reasons that black would be the one giving the checkmate - this is very sound reasoning. :) You just have to think outside the box.

cancel ×

### Reminds me (2)

#### Gambit Thirty-Two (4665) | more than 14 years ago | (#1445044)

Reminds me of when Chessmaster 6500 beat me in 5 moves when it was set on level novice.

I'm a REALLY bad chess player.

### Simple chess engine (1)

#### Imperator (17614) | more than 14 years ago | (#1445046)

Is there a simple engine that I can download? All you'd need to do is brute-force the possibilities. I might be very wrong, but 5 moves doesn't sound like it would take very long for a fast computer. Just grep through the results for the end move you want.

#### Anonymous Coward | more than 14 years ago | (#1445047)

Tsk tsk Hemos -- You can't leave the "http://" off when you post a link!

### Isn't this supposed to be a tech news site? (0)

#### Yebyen (59663) | more than 14 years ago | (#1445048)

I was under the impression that slashdot was for technology news and such... I don't know if this even really qualifies as "News for Nerds".

I'd appreciate it if this wasn't moderated down, but I know it will be. Oh well. At least don't do it for "Troll", cuz I'm not trolling. (Subliminal message to moderators: You know you want to...)

### Re:Isn't this supposed to be a tech news site? (0)

#### Anonymous Coward | more than 14 years ago | (#1445049)

News for nerds, not Tech news for nerds. Ah well. There are some articles that I don't think should be on Slashdot either -- The UAlbany Grad student who acts like a lizard or whatever, for example.

### Re:Isn't this supposed to be a tech news site? (1)

#### Yebyen (59663) | more than 14 years ago | (#1445050)

Oops I'm wrong this can be tech-related... see the post before me :-) This post is not off topic, because it is an addendum. Moderators: If a reply to a post has something to do with the original post, can it really be off topic?

### Re:Isn't this supposed to be a tech news site? (1)

#### Dopefish (33181) | more than 14 years ago | (#1445051)

Ahhh....but, chess is the oldest technology, using the oldest technology.

Or...something deep n' cheesy like that. Woooo...

### Re:Isn't this supposed to be a tech news site? (1)

#### aaron p. matthews (96130) | more than 14 years ago | (#1445052)

yeah, this really isn't NEWS because this is an old puzzle, but it's new to most of us. And furthermore, what 'nerd' doesn't play chess??

### white or black (3)

#### Bilibala (122348) | more than 14 years ago | (#1445053)

Doesn't say if the 5th move is going to be mated by black or white.... guess it'll be easier if it's black mate in 5

### Whats the point?? (0)

#### Anonymous Coward | more than 14 years ago | (#1445054)

It looks incredibly simple, but even the strongest players in world have been stumped by it.

Then what makes you think anyone here will do any better?

### Damn damn damn (1)

#### tpck (66866) | more than 14 years ago | (#1445055)

Damn damn damn. I can do it in *SIX* moves. I try again. :) I'd help if it said who wins. My bets on Black. :)

### Re:wh00t (0)

#### Anonymous Coward | more than 14 years ago | (#1445056)

No, we have a thing called "time zones". You obviously didn't notice. :)

### Re:Simple chess engine (4)

#### Rayban (13436) | more than 14 years ago | (#1445057)

Have you ever seen the tree for chess moves? The number of possible board combinations after 5 moves is way, way more than a trillion or so. I wish I could have the number here.

What I'm curious about, however, is if it could be possible to do some sort of backwards extrapolation. Here's a bit of an idea:

(8:51pm - restate my assumptions ;))

1. There are a finite number of squares for a knight to land on in 5 moves.
2. The rook must be able to make it to one of these squares in 5 moves, so the knight can take it.
3. The king must be able to make it to a square accessible from one of these squares for a mate to occur.

Keep in mind these assumptions, as well as the fact that you might be able to castle, and you can reduce your workload dramatically.

Now... Does the program state that white knight takes black rook, or vice versa?

### Re:Isn't this supposed to be a tech news site? (0)

#### Anonymous Coward | more than 14 years ago | (#1445058)

(Not to seem like a flaming AC, but) I don't. Honest. I just don't find it interesting.

### Re:Simple chess engine (1)

#### tpck (66866) | more than 14 years ago | (#1445059)

Good God, don't do that. :)

And its probably more than you think. :)

But honestly, computers are killing Chess. :( Soon it will be possible to have a computer brute force EVERY SINGLE MOVE in a game and beat a human opponent everytime. Personally, I think this sucks. I'm all for advances in computer science, but Chess is a HUMAN game. It should be played BY HUMANS against one another.

I'm personally going to work through it, I don't care how long it takes. :)

I do ask that if you, or anyone else, brute forces the answer, that you don't reveal it or try and win the prize. That's just not fair, really. Actually, I don't care about the prize, but don't spoil the riddle for everyone who wants to work through it -- thats like giving away the ending to a good book/movie, or telling the final score to someone who has taped a sports game. Discovery through diligence is good. Don't kill that, please.

### Re:Simple chess engine (1)

#### Restil (31903) | more than 14 years ago | (#1445060)

All possible chess games out to 5 moves (including both sides) would make cracking DES look like counting to 10.

Also, the real trick is that the knight must MATE the king, which means that first, the king can't be able to move to a safe space. It either needs to be trapped or all other available spaces need to be guarded. And secondly, the knight can not be captured by any peices from the other side.

-Restil

#### Kaufmann (16976) | more than 14 years ago | (#1445061)

Yes, I know, chess is the "game of kings" and all... but I've recently learned Go, and no one else seems to play it. Does anyone else on Slashdot play this game?

### 3 moves (0)

#### Anonymous Coward | more than 14 years ago | (#1445062)

1.e4 f5 2.f4 g5 3.Qh5X

### Re:Simple chess engine (0)

#### Anonymous Coward | more than 14 years ago | (#1445063)

If a computer can beat a human, than chess is a computational game. If we can no longer devise games that our creations cannot beat us at, we have effectively solved the strong AI problem.

### Chess is a lonely game... (1)

#### Bumbling_Booby (104908) | more than 14 years ago | (#1445064)

Knight --> fridge --> bourbon --> mate. It can be done in 4.

### Scholar's Mate (2)

#### ajs (35943) | more than 14 years ago | (#1445065)

I assume we are talking about Scholar's Mate, which is very similar to Fool's Mate. The two are described on this page [chesscorner.com] in some detail.

The answer, from that page, is "1.e4 e5 2.Bc4 Bc5 3.Qh5 Nf6 4.Qxf7#"

### Re:Whats the point?? (0)

#### Anonymous Coward | more than 14 years ago | (#1445066)

I think it's a good test of ESR's dictum. Think of this as a bug in the rules of chess - something to hack. /. is full of chess players. Well, "Given enough eyes, all bugs are shallow."

So let's prove it, folks.

### Re:wh00t (0)

#### Anonymous Coward | more than 14 years ago | (#1445067)

indeed. touche.

Of course, its quite amusing that "isn't this supposed to be a tech news site" gets hit by a moderator before my BLATENT first post.

idiot moderator? or are "slashdot/linux isn't as informative/elite/cool/fun/etc as it used ot be" posts are more annoying than "f1RsT p0St!!111!"?

### Re:Whats the point?? (0)

#### Anonymous Coward | more than 14 years ago | (#1445068)

because we have computers. while the tree of moves for 5 plays is prohibitive even for the largest cray (or beowulf, so those dorks won't say it), the rules set out allow some simplifying assumptions. Quite doable for anyone with decent programming skills, and a good understanding of chess.

I would, but I'm too busy reading my christmas present. "Metamagical Themas" by Hofstadter -- its the best non-fiction I have ever read. highly recommended.

### 6 moves is easy (2)

#### / (33804) | more than 14 years ago | (#1445069)

1. e2-e4 | b7-b6
2. f1-a6 | c8xa6
3. g1-f3 | g8-f6
4. g2-g3 | f6-d5
5. h1-g1 | d5-e3
6. g1-g2 | e3xg2++

It's whittling it down to just 5 that's tough.

### Re:Scholar's Mate (1)

#### Compuser (14899) | more than 14 years ago | (#1445070)

a queen, not a knight as required in a
puzzle. Also, you only have 4 moves, not 5.
I suppose, this puzzle is not about the
quickest mate, but a very specific one.

### move five? (1)

#### illusionm8 (90436) | more than 14 years ago | (#1445071)

that means ther can only be FOUR more moves after the 1.e4. looks impossible

### Re:Simple chess engine (1)

#### miahrogers (34176) | more than 14 years ago | (#1445072)

dang, think different for once.

all you need to fool a computer is a problem that CAN'T be solved with logic. like a riddle. Riddles are solved by defying logic.

### Re:Scholar's Mate (1)

#### tpck (66866) | more than 14 years ago | (#1445073)

Uhm, NO. :)

A game begins with 1.e4 and ends in the fifth move with knight takes rook mate.

This is the puzzle. KNIGHT TAKES ROOK MATE. That's what makes it hard. There are million ways to mate in 5 moves, but the usual way in which it is done is what makes this hard.

Please read the summary next time. Alot of people seem to be making this mistake...

### Re:What about Go? (OT) (1)

#### jflynn (61543) | more than 14 years ago | (#1445074)

I've played Go some. When I was going to school at Berkeley, and when there was a lunchtime Go club at a place I worked. Generally though, it's hard to find people to play Go in the US, I agree.

It's a more forgiving game for people like me who get things right the second time -- usually. :) It's also much, much harder to brute force.

### rook mate? (1)

#### miahrogers (34176) | more than 14 years ago | (#1445075)

what is rook mate and how does a knight take rook mate?

### Re:6 moves is easy (1)

#### tpck (66866) | more than 14 years ago | (#1445076)

Heh, I've been doing it a completly different way. Or rather, ways. I've got half a dozen ways with each black and white. But I can't do it in 5. This is nuts. I might post them later, if someone else doesn't first.

BTW, thats pretty wack notation :)

### Chess will NEVER EVER be solved by brute force (1)

#### jab (9153) | more than 14 years ago | (#1445077)

Let's say a chess game has on average 60 moves by each player, who on average chooses from 10 possibilities. That's 10^120 possible games. Let's say you have a petahertz computer that can evalutate a move per clock. 10^15 moves per second. Let's say every proton in the universe was such a computer and they all worked in parallel. That's 10^80 computers, according to physicist's estimates. Solution time is 10^120 / (10^80 * 10^15) = 10^35 seconds. Since a year only has pi * 10^7 seconds, it would take way over 10^27 years to solve, or about 10^17 times the lifetime of the universe. Chess WILL NEVER be solved by brute force.

### Re:TROLLIN' (0)

#### Anonymous Coward | more than 14 years ago | (#1445078)

Come on out of the closet...you know you'd like it if some sailors tied you up and took you for a ride. It's okay man it was obvious from your first word....

### MODERATIN' (0)

#### Anonymous Coward | more than 14 years ago | (#1445079)

AGAINST STOOPIDITY!

### You think that's bad... (1)

#### Kaht (122157) | more than 14 years ago | (#1445080)

I once played a chess game that, when you lost, the computer laughed at you...
And if you won, the board suddenly turned around, so you lost... and the computer laughed...
At least, I'm -pretty- sure this happened.

The more I think about it, the less it seems it really happened.

### Re:Chess will NEVER EVER be solved by brute force (0)

#### tpck (66866) | more than 14 years ago | (#1445081)

And 640k is all you'll ever need...

1. e2-e4 | g7-g6

2. g1-e2 | g8-f6

3. e2-f4 | h8-g8

4. f4-h5 | g8-g7

5. h5xg7+++

(mate)

### HEy (0)

#### Anonymous Coward | more than 14 years ago | (#1445083)

did anybody else get peyote for Christmas?

#### CausticPuppy (82139) | more than 14 years ago | (#1445084)

No, but I got a Diabolo for Christmas this morning, and I'm making it my new hobby.

### Re:Chess will NEVER EVER be solved by brute force (0)

#### Anonymous Coward | more than 14 years ago | (#1445085)

Well, that's fine, except that our friend said that THIS problem could be solved by brute force. Since there are only five moves, you can do the math and find that branching factor and depth and all that happy go lucky bullshit. The point is this problem can be solved by brute force. Course the full solution of chess will not anytime in the near future.

### Re:rook mate? (1)

#### CausticPuppy (82139) | more than 14 years ago | (#1445086)

That means that on the last move, a knight takes opponent's rook, and then it's checkmate.

### Riddles (1)

#### Super_Frosty (82232) | more than 14 years ago | (#1445087)

This riddle CAN be solved by a computer:

There once was a girl from Peru,
who filled her panties with glue.
She said with a grin,
they paid to get in,
and they'll pay to get out again, too!

Oh, wait, that's a limerick.

#### m3000 (46427) | more than 14 years ago | (#1445088)

For the unenlightened, what is Go?

### Boy oh boy (0)

#### Anonymous Coward | more than 14 years ago | (#1445089)

Come on you know you are dying to find out what it's like. Come on little boy. Get out of the closet and join the dark side..

### Re:chess (1)

#### Harry (2006) | more than 14 years ago | (#1445090)

Check out the black bishop dude.
Nice try though....

-harry

### Disappointed... (1)

#### Patzer (128015) | more than 14 years ago | (#1445091)

I'm pretty disappointed that ChessBase couldn't make up their own puzzle at least...
I'm almost positive I have this puzzle in a book in my house. (but then again, I have a *lot* of chess books ;-) )

Oh well...

For those interested, Hugh Courtney's annual Christmas Puzzles in the british magazine "Chess" are especially enteraining ;-)

### Re:Chess will NEVER EVER be solved by brute force (2)

#### Imperator (17614) | more than 14 years ago | (#1445092)

Actually, rumor has it Transmeta is working on subatomic Beowulf clusters.

Point taken. :)

### Re:chess (0)

#### Anonymous Coward | more than 14 years ago | (#1445093)

The trick to doing this was simple. You have to engineer it (ahem) so that the king that falls is trapped by his own pieces. In this example, the white king has already freed himself from this, so only black was left. A king trapped by his own pieces is asking to be mated by a knight. So, to get the number of moves required, use a knight to jump around and get into position and boom. mate.

l8rs all

(Greetings from A.C.)

#### Anonymous Coward | more than 14 years ago | (#1445094)

Look at http://www.usgo.org [usgo.org]

### Re:chess (0)

#### Anonymous Coward | more than 14 years ago | (#1445095)

Ahhh yes but what about f8 - g7? thus that is not a mate

### Re:Chess will NEVER EVER be solved by brute force (1)

#### jab (9153) | more than 14 years ago | (#1445096)

Oops, should have used "preview" -- it's really
10^7 times the lifetime of the universe to purely brute force chess, with
a superfast, universe sized, parallel per proton computer.
Same conclusion, though.

### Re:Simple chess engine (1)

#### rhyac (113670) | more than 14 years ago | (#1445097)

True, the tree is huge, but if you have a halfway decent tree pruning algorithm, you could eliminate the vast majority of the tree.

For example (disclaimer: I'm not a chess person - I hate the game), if the goal is a checkmate in five moves with the knight, then... moving the bishop to one position, and then right back to where it started.. Well, that whole subtree can be killed right off the start. It's obviously (well, unless there's some amazingly subtle chess strategy going on here) a waste of two moves.

That is how (as far as I am aware) chess games work. they create a tree of moves, and say 'okay, this is the goal..'. Then they prune the tree to lop off the bits that don't show much promise in attaining the goal, and try to brute-force the rest in search of an optimal solution. if it can't find a solution at a given depth in the tree, then it chooses the most 'promising' path, and selects it's move accordingly.

Correct me if I'm wrong. (Or if this is an insanely outdated technique that modern chess theorists just laugh at).

#### / (33804) | more than 14 years ago | (#1445098)

Here [chessbase.com] , assuming you only speak English.

### Re: does knight have to have the checkmate? (1)

#### illusionm8 (90436) | more than 14 years ago | (#1445099)

the knight can take the rook last, but the queen can make the checkmate? if you read the page, at the bottom, the guy who didn't figure it out argued that it wasnt stated properly. ..."When I told him the solution on the phone I could hear Mikhail Botvinnik gasp in the background. And Garry, who was convinced I had stated the problem incorrectly, couldn't believe that he and his students had missed it."...

### Re:Simple chess engine (1)

#### Anonymous Coward | more than 14 years ago | (#1445100)

Your assumption number 3 is flawed. It never said that the king must be mated BY the knight. In fact, I'll bet that the actual solution involves an "exposed" mate where the knight takes the rook, and exposes another piece, say the queen, that actually "mates" the king.

### Re:chess (1)

#### Rupes (61616) | more than 14 years ago | (#1445101)

>1. e2-e4 | g7-g6
>
>2. g1-e2 | g8-f6
>
>3. e2-f4 | h8-g8
>
>4. f4-h5 | g8-g7
>
>5. h5xg7+++
>
>(mate)

Sorry, this doesn't work - black's black bishop
takes the knight.

### wait wait wait! (1)

#### illusionm8 (90436) | more than 14 years ago | (#1445102)

the knight can take the rook last, but the queen can make the checkmate? like the knight takes the rook and moves out of the way for a queen to make the checkmate. get what im saying?

if you read the page, at the bottom, the guy who didn't figure it out argued that it wasnt stated properly.

..."When I told him the solution on the phone I could hear Mikhail Botvinnik gasp in the background. And Garry, who was convinced I had stated the problem incorrectly, couldn't believe that he and his students had missed it."...

### Re:Scholar's Mate (2)

#### ajs (35943) | more than 14 years ago | (#1445103)

Yes, it seems that I missed the crucial bit about the knight. I'll have to work on this one....

#### Kiwi (5214) | more than 14 years ago | (#1445104)

The world champion Emmanual Lasker said that Go was a superior game to chess.

- Sam

### Re:wait wait wait! (1)

#### Crixus (97721) | more than 14 years ago | (#1445105)

the knight can take the rook last, but the queen can make the checkmate? like the knight takes the rook and moves out of the way for a queen to make the checkmate. get what im saying?

Discovered check(mate).

### Re:wait wait wait! (1)

#### tpck (66866) | more than 14 years ago | (#1445106)

I assume that the Queen can make the mate, so long as the knight takes the rook. But I haven't found a way to make it work with the Queen in less than 6 moves. :(

I think I found the solution though. Or, rather, I think I know how to solve. Working on it now. :)

### Verify this solution for me... (1)

#### Chagrin (128939) | more than 14 years ago | (#1445107)

Apologies for my lack of knowledge of chess notation...

h7 - h6 (black king's rook's pawn)
g1 - f3 (white king's knight)
g7 - g6 (black king's knight's pawn)
f3 - e5 (white king's knight)
f7 - f6 (black king's bishop's pawn)
e5 - g6 (white king's knight)
a7 - a6 (black queen's rook's pawn - irrelevant)
d1 - h5 (white queen)
a6 - a5 (black queen's rook's pawn - irrelevant)
g6 - h8 (white king's knight takes rook)

I think that satisfies all of the requirements.

### Brute force solution (1)

#### Qeyser (6788) | more than 14 years ago | (#1445108)

A chess solution may be possible if you consider that most algorithms aimed at this problem are only going to consider reasonable moves and plausible board positions. Kind of like "guided" brute force.

Checkers on the other hand, - I've read somewhere that there are over 10^120 plausible board positions: orders of magnitude greater than the estimated number of particles in the universe ; )

-q

### Re:Verify this solution for me... (0)

#### Anonymous Coward | more than 14 years ago | (#1445109)

that would be whites 6th move

### Uhhh... no? (1)

#### tpck (66866) | more than 14 years ago | (#1445110)

The spoiler that's been posted is not a solution? I won't repeat it here, just in case, but as far as I can see, black checks white at one point, and white never moves out of check. If this is 'thinking outside the box' and this is the actual solution, this puzzle is useless. :) Breaking the rules to solve the puzzle is, in my opinion, cheating. Did I miss something?!

### Re:Verify this solution for me... (2)

#### jellicle (29746) | more than 14 years ago | (#1445111)

It's a very good solution. except that that is White's sixth move, not fifth.
--
Michael Sims-michael at slashdot.org

### Close, but incorrect (1)

#### tpck (66866) | more than 14 years ago | (#1445112)

Mate is given on whites 6th move, so this isn't a valid solution. Close though. :)

### Re:Simple chess engine (1)

#### [Sn] (8014) | more than 14 years ago | (#1445113)

You may reduce the workload dramatically, but you still have too much workload for even the most powerful of computers to compute in a reasonable amount of time, because the problem is still not "trivial" (a term my professor used to use to describe easy, ie polynomial or in some cases simply sub exponential time). I have worked on a number of similar problems (ie, given 4 particular pieces, give the one shortest winning sequence). This search tree is incredibly huge unless you utilize some of the heuristic ideas that algorithm genius' (as I call them) have determined to be most efficient for games such as chess, but that still requires that you know how to judge a good chess board, which is sadly something that I suck horribly at. If I remember correctly, the best algorithm I could come up with took approximately 4 minutes on a Pentium II 400, 128M RAM to guarantee the winning moves for a very limited board state. Given that the problem is not a limited state (in that any algorithm still must consider a much larger number of pieces, I dont think we would see a computer calculatable solution for this problem any time in the near future). This is why games such as the chessmaster series make us algorithm design guys drool. [Sn]

### I think i got it (1)

#### Anonymous Cowpoop (128906) | more than 14 years ago | (#1445114)

I must be missing something... maybe the pieces are wrong... I dont understand the letter-number thing... Move the right knight 2 forward and 1 left; 2 right and 1 forward; 2 forward and 1 left; 2 forward and 1 left. Gee that was really easy... could someone tell me how the board is lettered-numbered?

### Re:Verify this solution for me... (0)

#### Anonymous Coward | more than 14 years ago | (#1445115)

Close, but no cigar. You took one move too many.

1. e2 - e4 h7 - h6
2. g1 - f3 g7 - g6
3. f3 - e5 f7 - f6
4. e5 - g6 a7 - a6
5. d1 - h5 a6 - a5
6. g6 - h8

### Chess Board Numbering (1)

#### Zaffle (13798) | more than 14 years ago | (#1445116)

From left to right, when sitting on Whites side of the table, is A-H. From the white side to the black side, is 1-8.
So D1 is Whites Queen.

When stating a move, the result is sometimes stated by itself, when its obvious what happened.
(eg: e4, theres only one piece that can make that move, the pawn at e2).

### Possible Solution (1)

#### asmussen (2306) | more than 14 years ago | (#1445117)

1 E2-E4 D7-D6
2 D1-E2 C8-G4
3 E2-E3 B8-C6
4 A2-A3 C6-D4
5 A3-A4 D4-C2++

Any problems with this one? The above spoiler does not work as white fails to move out of check at one point.

### Re:Possible Solution (0)

#### Anonymous Coward | more than 14 years ago | (#1445118)

The knight has to take a rook as the last move.

Doh!

### Re:Possible Solution (1)

#### tpck (66866) | more than 14 years ago | (#1445119)

Sorry, but at no point does the knight take the rook, right?

Rules say: A game begins with 1.e4 and ends in the fifth move with knight takes rook mate..

You've got Knight takes Pawn mate.

### Definitely not the solution!! (0)

#### Anonymous Coward | more than 14 years ago | (#1445120)

what about pawn c2-d3???? what the heck? that's not mate...that was just a dumb check..am i missing something?

### Re:Possible Solution (1)

#### Rupes (61616) | more than 14 years ago | (#1445121)

>
>1 E2-E4 D7-D6
>2 D1-E2 C8-G4
>3 E2-E3 B8-C6
>4 A2-A3 C6-D4
>5 A3-A4 D4-C2++
>
>Any problems with this one? The above spoiler >does not work as white fails to move out of check >at one point.

I believe that a knight must actually take a rook, which invalidates this answer...

### Re:Possible Solution (2)

#### jellicle (29746) | more than 14 years ago | (#1445122)

But it doesn't end with knight takes rook.
--
Michael Sims-michael at slashdot.org

### Re:Possible Solution (1)

#### matthewo (89808) | more than 14 years ago | (#1445123)

You have to capture a rook with the last move involving the knight.

### Re:Possible Solution (1)

#### asmussen (2306) | more than 14 years ago | (#1445124)

Whoops. That's what I get for not paying close enough attention... :)

### Here's my solution (0)

#### Anonymous Coward | more than 14 years ago | (#1445125)

1. e4 b8-c6
2. a2-a4 c6-b4
3. a1-a3 b4-c2
4. a1-d4 c2-b4
5. g1-e2 b4-d3++

However, in my opinion white would need to a terrible player. :)

### Discovered check in 5 1/2... (0)

#### Anonymous Coward | more than 14 years ago | (#1445126)

Alot of people have been saying that it might be a trick(discovered check), here is a way to do it in 6.

Be aware that this solution only involes white working hard, and that black is just wasting away moves after the first. If you can maybe use those wasted moves, it might lower the move count down by one.

1. e2-24, g7-g5
2. d1-h5, g5-g4
3. g1-f3, g4-g3
4. f3-g5, g3xh2
5. g5-f7, a7-a6
6. f7xh8

If you feel like it, this might be in 5 moves(ignoring the first)....

### Re:Possible Solution (NOT!) (0)

#### Anonymous Coward | more than 14 years ago | (#1445127)

knight takes rook mate. if you smash the rook, the king still lives!! so, not a real solution.

### OMG. (1)

#### tpck (66866) | more than 14 years ago | (#1445128)

I just had a very disturbing thought.

What if WHITE Knight takes BLACK Rook, and this causes mate for WHITE? Surely its not that. But it is said: And Garry, who was convinced I had stated the problem incorrectly, couldn't believe that he and his students had missed it.

If its some silly little trick in the wording, I'm going to be anoyed. Very much so. Grr. Of course, in the meantime, I'm not getting anywhere with this thing. 101 ways to mate in 6, but none in 5. Sigh.

I'm thinking maybe you need to promote a Pawn? Just a though. Anyone else out there actually working on this?

### Black eh? with an odd # of moves and white start? (0)

#### Rares Marian (83629) | more than 14 years ago | (#1445129)

I doubt it. Very much.

If I'm not mistaken you're not allowed to commit suicide. That is you cannot move so that w/o the oppnent making a move you put your king in harm's way.

1. White 2. Black 3. White 4. Black 5. White

Now unless 2 + 2 = 5, (hint hint: the chess game at the end of 1984), there's no way black wins.

### Re:Possible Solution (1)

#### illusionm8 (90436) | more than 14 years ago | (#1445130)

the condition is to take a rook on the last move. you didn't.

### Re:Here's my solution (0)

#### Anonymous Coward | more than 14 years ago | (#1445131)

Move 4 doesn't work, 3. a1-a3 b4-c2(check).

White would have to move his king out of check, not move his rook over like you have it.

### Re:Here's my solution (0)

#### Anonymous Coward | more than 14 years ago | (#1445132)

What game are you playing? - it's not Chess...

In Chess, virtual pieces are not created at a1.

Hmmm.

### Re:OMG. (1)

#### illusionm8 (90436) | more than 14 years ago | (#1445133)

promoting a pawn? wouldn't that invlove much more than 5 moves?

### Nerdyness =technology. (0)

#### Rares Marian (83629) | more than 14 years ago | (#1445134)

Go read IBM or HP's internal memos if that's what you want.

And frankly I think it shouldn't be moderated down only so that we get more discussion about how disturbingly narrow minded your comment is.

### Eh? Looks nice (1)

#### kaputsk (120446) | more than 14 years ago | (#1445135)

I think you mean: 1. e4 Nc6 2. a4 Nb4 3. Ra3 Nxc2 4. Rd3 Nb4 5. Ne2 Nxd3# Eh?

1. e4 b8-c6
2. a2-a4 c6-b4
3. a1-a3 b4-c2
4. a3-d3 c2-b4
5. g1-e2 b4-d3++

### Re:Here's my solution (0)

#### Anonymous Coward | more than 14 years ago | (#1445137)

You are a little confused. In 3 you move the white rook from A1 to A3. Then in move 4 you move something from A1 to D4. I am assumming that you really meant 4. D3 to D4 but it is impossible to tell.

Further whatever it is you are moving in move 4 still doesn't block the check that the king is under from move 3. b4 to c2.

These must be legal moves.

### Re:6 moves is easy (0)

#### Anonymous Coward | more than 14 years ago | (#1445138)

nope...even 6 moves is wrong. the king can move to e2 or g1

### Re:You think that's bad... (2)

#### cheese63 (74259) | more than 14 years ago | (#1445139)

I had this handheld game, double dragon. i sucked real bad at it. once the batteries went bad while i was on a real high level too. i got so pissed off i smashed the fucking thing with a hammer. moral of this story, don't make offtopic troll posts on christmas, unless you have a real low karma like me.

### Re:nope (1)

#### illusionm8 (90436) | more than 14 years ago | (#1445140)

your 3rd move. you cannot go from a3-d3 because you are ignoring the check that the knight has on the king.

### Re:Black eh? with an odd # of moves and white star (1)

#### tpck (66866) | more than 14 years ago | (#1445141)

Heh, actually, I've since changed my mind. I just thought it might be black, cuz white is too obvious...

### Re:Isn't this supposed to be a tech news site? (1)

#### cheese63 (74259) | more than 14 years ago | (#1445142)

you can be moderated to offtopic posting anything. just read some of my posts...

### Re:OMG. (1)

#### tpck (66866) | more than 14 years ago | (#1445144)

But so would everything else... hehe. I dunno, I'm lost. :)

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