Slashdot Mirror
A Christmas Chess Puzzle
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.
"
2. a4 b4
3. a1-a3 c2
4. a3-d3 b4
5. g7-e2 d3++
-->
Update: 12/25 11:50 by michael : Well, I thought I figured it out, but I was wrong.
1. e4 b8-c62. a4 b4
3. a1-a3 c2
4. a3-d3 b4
5. g7-e2 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.
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.
http://www.chessbase.com/puzzle/puzzle.h tm
Gates' Law: Every 18 months, the speed of software halves.
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
do not in anyway underestimate anybody, especially yourself
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?
æeee!
I assume we are talking about Scholar's Mate, which is very similar to Fool's Mate. The two are described on this page in some detail.
The answer, from that page, is "1.e4 e5 2.Bc4 Bc5 3.Qh5 Nf6 4.Qxf7#"
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.
"If one is really a superior person, the fact is likely to leak out without too much assistance" -- John Andrew Holmes
Point taken. :)
Gates' Law: Every 18 months, the speed of software halves.
Here, assuming you only speak English.
"If one is really a superior person, the fact is likely to leak out without too much assistance" -- John Andrew Holmes
It's a very good solution. except that that is White's sixth move, not fifth.
--
Michael Sims-michael at slashdot.org
But it doesn't end with knight takes rook.
--
Michael Sims-michael at slashdot.org
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.
2. The mate is to the king side (the side with no queen- think of the way a knight would have to move...)
3. It's not a discover mate. That's because b1/b8 to a1/a8 takes at least four moves- which doesn't leave enough time for a relevant queen or bishop move by either side (black must move a pawn.)
4. The mate does not involve moving any rooks. There are only four positions from which a knight can mate a king on e1/e8; there isn't enough time to move a rook somewhere relevant and make sure it's not protected by any other pieces.
5. The mate is apparently by black. I say this because, if it's by white, black only has four moves- but a black mate gives black five moves, which should be the least amount you need (assuming e2-e4 is irrelevant- it's a red herring.)
That's what I was able to figure out...good luck
I have discovered a truly marvellous solution to this problem, which however this textbox is not large enough to contain.
(Now if somebody else actually publishes the solution it will at least be named after me.)
"He who takes credit for everything, is bound to get credit for something."
-My Dad
Except that's not how moves are counted in chess. A "move" in chess counts both white and black, so a mate in the fifth move could end with either white or black moving:
1. White Black 2. White Black 3. White Black 4. White Black 5. White
or
1. White Black 2. White Black 3. White Black 4. White Black 5. White Black
The king is on e1, so there's no way in heck he can get over to g1. As for e2, that's covered by the bishop on a6. He is truly checkmated, for all the good it does in this contest.
"If one is really a superior person, the fact is likely to leak out without too much assistance" -- John Andrew Holmes
E2 - E4 (the starting move required by white)
D7 - D6 (black queen's pawn)
F2 - F4 (white king's pawn)
G8 - F6 (black king's knight)
E1 - F2 (white king)
F6 - G4 (black king's knight - check)
F2 - G3 (white king)
G4 - F2 (black king's knight)
G1 - F3 (white king's knight)
F2 - H1 (black king's knight takes white king's rook - checkmate)
I/O Error G-17: Aborting Installation
Hehe. If you want to locate tech news on Christmas, be my guest.
Yeah, I'm that guy.
-=-=-=-=-
-=-=-=-=-
My mom's going to kick you in the face!
anyone who wants to chat about this or wants to share ideas, come to:
#chess
slashnet.org
1. Does it involve MS? If so, 75% of the people will hate the MS led answer, regardless of how it came about. .005% to the 5 first posters. .995 will have discussions on topic, but their message threads will be spaced apart by the rest of the banter.
2. FreeBSD vs Linux? 10% will get so caught up on what OS Netscape/Lynx/Opera was running on to post the ideas to each other, they will never get anywhere. The MS people are exluded above. Mac users, who uses a mac? (running away)
3.
4. 14% will somehow discuss moderation or how checkers and go have similar problems. Thus starting new threads.
5. The rest
There was hope..
---
-
ping -f 255.255.255.255 # if only
The brief version (for those who don't care to click on the link the previous AC provided):
Go is a game played worldwide, but has the strongest "community" in the Orient, where there are Go professionals and professional Go commentators and writers (especially in Japan). The rules are fairly simple but unfortunately not simple enough to reproduce here (especially since I'm doing this from memory). Very briefly, it's played on the intersections of a 19x19 grid of lines with pieces called stones. Players alternate placing stones on the grid, attempting to capture as much territory as possible by making it impossible for the opposing player to place uncapturable stones inside the territory. A stone or group of stones is captured if it is completely surrounded by enemy stones, so if a group can't be surrounded it can't be captured. Captured stones count against a player at the end of the game, so efficiency is paramount, both in securing territory and in trying to attack it.
I remember reading a summary of a book written over 25 years ago comparing chess and go in the context of Eastern vs. Western military philosophy (this was toward the end of the Vietnam war). The author's thesis was that in chess, the object is to capture a particular piece, and a player can sacrifice as many of his pieces as necessary to capture the king. In go, the goal is not to capture particular pieces (in fact, every go stone is just as powerful as every other -- it's how groups of stones are deployed that make them weak or powerful), but to capture territory, and as I mentioned above, the more efficient you are at it, the better go player you'll be,
--
Someone you trust is one of us.
As fast as the chess possiblities rise, they are constrained by the possible movements of the pieces, the smaller board size, etc. Go rises orders of magnitude faster, and no computer program has to date (to my knowledge, mostly parrotting things I've skimmed here) been able to play even on a beginner's level. Fascinating stuff.
Not that this helps solve the Fermat's theorem of chess or anything.
DO NOT LEAVE IT IS NOT REAL
Well, gnuchess is a Free Software chess program. You can search for it on freshmeat. I am presently working on an optimized brute-force solution to this.
A *move* is 1> White Black . What you have said is usually termed as a ply (Ply == 1/2 move)
I can throw myself at the ground, and miss.
try looking into igs (international go server) ;) clients are available for most platforms, and at any given time there's about a hundred games going on involving everyone from 30 kyu beginners to like 9 dan masters.
igs is kindof like a go equivalent of gamespy, except for the fact that it predates gamespy by at least four years
here's their url if you're interested:
http://igs.joyjoy.net/
-- the opinions stated above aren't those of my employer. in fact, they're probably not even my own. you know what, ju
Last time I checked, this was "News for Nerds", not "Tech News for Nerds".
Whether you love chess or hate it, you have to admit it's a passtime in which many nerds (and geeks too, for that matter) engage, and is thus "Stuff That Matters" for a large contingent of our colleagues.
So, in summary, Hemos; you go, girl. Keep posting that chess shit.
Note to the clueless; Hemo is not female. I am aware of this. Get off the computer and do something else for a while. Watch Springer or something.
Yup, I play a bit. No, I'm not good, but I do play it. For a computer player get gnugo (requires CGOBAN IIRC, both oss).
1. e4 f5 2. Ne2 g5 3. Nf4 h5 4. Ng6 a5 5. Qxh5 a4 6. Nxh8#
...a5.
Ok, so you see that I've wasted a black move on 4.
Can that move be used to re-position the rook so that this works? I was thinking earlier that the solution had to begin with 1. e4 h5 2. Qxh5 Rxh5, with white's bishop providing the checkmate, but I just don't see how that works, even if black's rook moves to the center....
Hope this helps.
Okay, if I'm thinking "outside the box enough", I think this might satisfy the solution.
A game begins with 1.e4 and ends in the fifth move with knight takes rook mate.
That is the problem. Now, it's possible, that with a slight bit of imagination (which I have an abundance of), the sentence could be read as such: "A game begins with 1.e4, and ends in the fifth move with knight taking rook, Mate."
Just re-read the sentence in your best Aussie impression, and you've got it. Doesn't matter the sequence of moves, long as the fifth move ends in knight taking rook...
Too far outside the box??? I dunno... Never was all that great at chess...
the notation is less whacked, wacky, and wack if it's
1. e4 | b6
2. Ba6 | Bxa6
...
For the queen to get involved it takes 2 extraneous moves if you're black, which you just don't have to spend if you're getting the knight over there to claim the rook.
If you're white, then you can do an uncovered mate in 6 like this, but that doesn't solve the puzzle:
(white) | (black)
1. e2-e4 | g7-g5
2. d1-h5 | a7-a6
3. g1-f3 | b7-b6
4. f3-e5 | c7-c6
5. e5xf7 | c6-c5
6. f7xh8++
"If one is really a superior person, the fact is likely to leak out without too much assistance" -- John Andrew Holmes
Look at all the pieces on the board. For there to be a stalemate, all of one player's pieces can't move. It just can't happen after 5 moves.
"If one is really a superior person, the fact is likely to leak out without too much assistance" -- John Andrew Holmes
1. e4 | Nf6
2. f3 | Nxe4
3. Qe2 | Ng3
4. Qxe7+ | Qxe7+
5. Kf2 | NxF1#
If yours is the solution, then it's because the English language is ambiguous when it comes to the word "with": either it means "by means of" (in which case your solution fails) or it means "accompanied by" (in which case your solution succeeds, although perhaps comment #145 is better in that the knight-takes-rook move also occurs during the 5th move).
I suspect it's not supposed to be a word-play like that, though, because there are several possible solutions that make use of that trick, and this puzzle probably only has one brilliant solution. But maybe I have too much faith in John Nunn.
"If one is really a superior person, the fact is likely to leak out without too much assistance" -- John Andrew Holmes
Correct Solution is 1. e4 | Nf6 2. f3 | Nxe4 3. Qe2 | Ng3 4. Qxe7+ | Qxe7+ 5. Kf2 | NxF1# "make my taco salads pretty, jimmy!" - ucb
This was posted earlier by Spicy Biscuit. I'm just writing it down in a different format for those who prefer it:
:)
1. e2-e4 g8-f6
2. f2-f3 f6-e4
3. d1-e2 e4-g3
4. e2-e7 d8-e7
5. e1-f2 g3-h1++
Very ingenious solution
æeee!
(Frederic: creating a Slashdot account takes only a few seconds. All you need is to remember a password.)
If we have by the end of February, I say we can brute force this. There are only eight or nine unknown plies; if we assume that there are around 20 possible moves per ply, which I think is a reasonable order of magnitude (``reasonable'' logarithmically, of course), this makes 500 billion combinations, and at a very very reasonable rate of 10^5 positions analyzed per second (a quite conservative estimate: most engines will do better than that on a modern computer, and they are evaluating, not just checking for mate) this takes 60 days. Put in two or three computers full time for two weeks and we have the answer for sure. And probably much before that, since we know, for example, that the eighth or ninth ply has to be ``knight takes rook''.
Does anyone know enough about the internals of either crafty or (the new 5.00) GNU chess so that we can extract their movegen and set them running? From the cursory glance I gave them, the source looks like a horribly tangled mess (less so in GNU chess than in crafty, but still rather unappealing).
Still, it would be more satisfactory to solve it ourselves. ``When you have eliminated the impossible, Watson,'' said Holmes, ``whatever remains, however improbable, must be the solution.''
While I understand that you weren't actually responding to my post, just using it as an excuse to toot your own horn and engage in a polemic against people who you don't feel meet your standards for chess skills, I think you're doing a tremendous disservice to the community by discouraging people from exploring.
If someone makes a post that clearly indicates they're interested in something, but not expert level at it, a much more community-oriented response would be to gently guide them to a greater understanding of the subject.
I mean, the guy who posted the solution could have insulted *YOU* for not meeting his standards of chess skill.