I challenge you!

For the discussion of math. Duh.

Moderators: gmalivuk, Moderators General, Prelates

How good at Dots and Boxes are you?

random play
2
4%
avoid giving other player boxes at start, then see who wins.
12
26%
leave all but last two boxes in long chains/use sacrifices
20
43%
somewhat understand how to keep control of board
8
17%
not sure I can be beat/use Sprague-Grundy thm
4
9%
 
Total votes: 46

of.hippo
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I challenge you!

Postby of.hippo » Wed Feb 18, 2009 1:56 am UTC

http://en.wikipedia.org/wiki/Dots_and_boxes

Does anyone out there claim to be an expert at the [usually] paper "dot game"? Like, better than just knowing not to take the last two boxes of a chain? Would anyone like to play me? Does anyone know any good places to play or could someone code it for me and put it online?

Thanks!

Buttons
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Re: I challenge you!

Postby Buttons » Wed Feb 18, 2009 2:57 am UTC

Funny you should post this today. You didn't happen to go to this, did you?

hnooch
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Re: I challenge you!

Postby hnooch » Wed Feb 18, 2009 6:36 am UTC

I voted leave long chains. But only because I've seen that book before and made it through a chapter or two.

of.hippo
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Re: I challenge you!

Postby of.hippo » Wed Feb 18, 2009 8:44 am UTC

I've heard of that book before but I've been studying the game a lot more recently. I wonder if my findings have produced a similar strategy the book does. Of course, I'm no professor so I'm sure this person would win.

I wonder who got me started at this... *looks at hnooch*

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Macbi
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Re: I challenge you!

Postby Macbi » Wed Feb 18, 2009 9:28 am UTC

I play dots on:
http://www.yourturnmyturn.com
http://www.littlegolem.net
vying.org
I have a rating of >2000 so I totally accept your challenge!

You'll see on the talk page of that wikipedia article that I was going to re-write it. As it turns out I'm just too lazy. Berlekamp's book is excellent (even if it does focus a bit heavilly on purely mathematical issues later on), but you can also learn lots from this webpage. That page focuses on the games at the Yahoo! real time dots games, which I tend to avoid since 4*4 and 9*9 are such silly board sizes. Give me 5*5 any day.

Internets to the person who spots the winning move in my avatar!

EDIT: Who else voted in the poll that they were at the highest level?
    Indigo is a lie.
    Which idiot decided that websites can't go within 4cm of the edge of the screen?
    There should be a null word, for the question "Is anybody there?" and to see if microphones are on.

of.hippo
Posts: 10
Joined: Mon Oct 29, 2007 10:05 pm UTC

Re: I challenge you!

Postby of.hippo » Thu Feb 19, 2009 10:29 pm UTC

Wow! This is exactly what I was hoping someone would post. I really want to get better and it sounds like I have a long way to go! I'd love to play a game although calling it a 'challenge' at this point would be silly.

Oh, xkcd, I love you, your readers and your awesomeness.

stephentyrone
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Re: I challenge you!

Postby stephentyrone » Thu Feb 19, 2009 11:32 pm UTC

Macbi wrote:EDIT: Who else voted in the poll that they were at the highest level?


I did. I've took a few graduate classes with Berlekamp when I was at Berkeley.
GENERATION -16 + 31i: The first time you see this, copy it into your sig on any forum. Square it, and then add i to the generation.

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mrbaggins
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Re: I challenge you!

Postby mrbaggins » Fri Feb 20, 2009 8:58 am UTC

Macbi wrote:I play dots on:
http://www.yourturnmyturn.com
http://www.littlegolem.net
vying.org
I have a rating of >2000 so I totally accept your challenge!

You'll see on the talk page of that wikipedia article that I was going to re-write it. As it turns out I'm just too lazy. Berlekamp's book is excellent (even if it does focus a bit heavilly on purely mathematical issues later on), but you can also learn lots from this webpage. That page focuses on the games at the Yahoo! real time dots games, which I tend to avoid since 4*4 and 9*9 are such silly board sizes. Give me 5*5 any day.

Internets to the person who spots the winning move in my avatar!

EDIT: Who else voted in the poll that they were at the highest level?


There's a winning move at that point specifically? Good lord.
Why is it that 4chan is either infinitely awesome, infinitely bad, or "lolwut", but never any intermediary level?

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Macbi
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Re: I challenge you!

Postby Macbi » Fri Feb 20, 2009 9:23 am UTC

of.hippo wrote:Wow! This is exactly what I was hoping someone would post. I really want to get better and it sounds like I have a long way to go! I'd love to play a game although calling it a 'challenge' at this point would be silly.

Oh, xkcd, I love you, your readers and your awesomeness.
If you ever do play on any of those sites, watch out for a guy called wccanard, he's a really good dots and boxes player, and he's also a mathematician, so he cares about the theoretical aspect of the game. His advice for getting better is just to practice loads; play against people slightly better than you and analyse how they beat you. The best site is Little Golem (ie. it has the widest range of players), there's also a site called Jij Bent! which is supposed to have lots of good players, but I've stayed away from it 'cause it's Dutch.

stephentyrone wrote:
Macbi wrote:EDIT: Who else voted in the poll that they were at the highest level?
I did. I've took a few graduate classes with Berlekamp when I was at Berkeley.
I am SO envious.
mrbaggins wrote:
Macbi wrote:Internets to the person who spots the winning move in my avatar!
There's a winning move at that point specifically? Good lord.

Yep, it involves a "trick" though, there's not always a winning move so early on. Here's another puzzle, this one was constructed by wccanard:

Image(A to move)
Last edited by Macbi on Fri Feb 20, 2009 5:04 pm UTC, edited 1 time in total.
    Indigo is a lie.
    Which idiot decided that websites can't go within 4cm of the edge of the screen?
    There should be a null word, for the question "Is anybody there?" and to see if microphones are on.

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mrbaggins
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Re: I challenge you!

Postby mrbaggins » Fri Feb 20, 2009 10:34 am UTC

You'd probably really like a game called "Go". Pretty sure it's chinese in origin. It's also the game "Stones" in the Wheel of Time series by robert jordan.

Great fun.

Is the winning move in your coloured puzzle a horizontal line, if you numbered dots from top left as (0,0), between 3,5 and 4,5? That is, 5th row of dots from the top, between dots 3 and 4 (the middle)?

Nevermind, it's not... I can't see why the only move that doesn't immediately give a box isn't the best move... but that's too obvious.

Wait, yes I can. Because of my first suggestion, that move sucks.

No idea on the answer. Giving up now.
Why is it that 4chan is either infinitely awesome, infinitely bad, or "lolwut", but never any intermediary level?

itaibn
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Re: I challenge you!

Postby itaibn » Fri Feb 20, 2009 10:24 pm UTC

I think I solved your second puzzle (the one where some squares are already coloured):
Spoiler:
With coordinates of dots being amount-right-amount-down, the solution is 3-3 right. If B tries keeping control (3-2 down, 1-2 down), A does 2-5 down and 3-4 down and manages to win by 3 points. If B loses control and tries the same trick against you, you will still win by 1 point.
I NEVER use all-caps.

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Macbi
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Re: I challenge you!

Postby Macbi » Sat Feb 21, 2009 10:36 am UTC

The "best" notation is to lable the dots and the spaces with the letters a to k along the bottom, and then lable the dots and the spaces going up with 1-11. That way each dot, box, and edge has a unique coordinate. a1 is the dot in the bottom left. f5 is the edge below the middle box. h8 is the box one in diagonally from the top right.
itaibn wrote:I think I solved your second puzzle (the one where some squares are already coloured):
Spoiler:
With coordinates of dots being amount-right-amount-down, the solution is 3-3 right. If B tries keeping control (3-2 down, 1-2 down), A does 2-5 down and 3-4 down and manages to win by 3 points. If B loses control and tries the same trick against you, you will still win by 1 point.

I don't quite understand your notation, do you mean f5 in my notation? Then:
Spoiler:
B takes all three boxes and plays d1
    Indigo is a lie.
    Which idiot decided that websites can't go within 4cm of the edge of the screen?
    There should be a null word, for the question "Is anybody there?" and to see if microphones are on.

itaibn
Posts: 142
Joined: Mon Dec 29, 2008 7:06 pm UTC

Re: I challenge you!

Postby itaibn » Sat Feb 21, 2009 3:07 pm UTC

Macbi wrote:
itaibn wrote:I think I solved your second puzzle (the one where some squares are already coloured):
Spoiler:
With coordinates of dots being amount-right-amount-down, the solution is 3-3 right. If B tries keeping control (3-2 down, 1-2 down), A does 2-5 down and 3-4 down and manages to win by 3 points. If B loses control and tries the same trick against you, you will still win by 1 point.

I don't quite understand your notation, do you mean f5 in my notation? Then:
Spoiler:
B takes all three boxes and plays d1

Spoiler:
Yes, I do mean f5. And if B plays d1, can't A just play c2?

edit/add: OK, I see now why I was wrong. But to avoid breaking internet rules, Macbi is like a nazi for forcing his opinion on me.
Last edited by itaibn on Sat Feb 21, 2009 4:47 pm UTC, edited 1 time in total.
I NEVER use all-caps.

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Macbi
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Re: I challenge you!

Postby Macbi » Sat Feb 21, 2009 3:59 pm UTC

itaibn wrote:
Spoiler:
Yes, I do mean f5. And if B plays d1, can't A just play c2?

Spoiler:
Then B takes the box and plays e2. A is one down now, and she can either take all four and give away four, or she can sacrifice them by playing e4, and then get the four in the chain. Either way B wins 13-12.
    Indigo is a lie.
    Which idiot decided that websites can't go within 4cm of the edge of the screen?
    There should be a null word, for the question "Is anybody there?" and to see if microphones are on.

++$_
Mo' Money
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Re: I challenge you!

Postby ++$_ » Sun Feb 22, 2009 6:24 am UTC

Spoiler:
A opens the long chain at right. If B gives up control, he has to play in the left-hand part. Now, d1 is met by d3, and B must open a 7-chain. If If B sacrifices either of b2 or d4, then A accepts the sacrifice and counters with the other, getting 6. If B sacrifices f2, then A accepts and responds with d1, getting 7. If B makes any other play, A takes bdf6 and responds at e2. B then has to give up two more boxes, and loses.

On the other hand, if B keeps control, then A takes the two boxes and plays at f4. If B keeps control again, he'll lose to d1, when he must sacrifice at least one box. So he has to take bdf6, and then is forced to make a play. If he plays at d1, A takes c2 and B has to give up the loop (so A ends up with 14 boxes). If he sacrifices b2, then A takes it and B still has to give up the loop. If he plays anywhere else, A takes the three boxes and wins immediately.

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Macbi
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Re: I challenge you!

Postby Macbi » Sun Feb 22, 2009 9:22 am UTC

++$_ wrote:
Spoiler:
A opens the long chain at right. If B gives up control, he has to play in the left-hand part. Now, d1 is met by d3, and B must open a 7-chain. If If B sacrifices either of b2 or d4, then A accepts the sacrifice and counters with the other, getting 6. If B sacrifices f2, then A accepts and responds with d1, getting 7. If B makes any other play, A takes bdf6 and responds at e2. B then has to give up two more boxes, and loses.

On the other hand, if B keeps control, then A takes the two boxes and plays at f4. If B keeps control again, he'll lose to d1, when he must sacrifice at least one box. So he has to take bdf6, and then is forced to make a play. If he plays at d1, A takes c2 and B has to give up the loop (so A ends up with 14 boxes). If he sacrifices b2, then A takes it and B still has to give up the loop. If he plays anywhere else, A takes the three boxes and wins immediately.
Yes! This is the right answer. Nice one.
    Indigo is a lie.
    Which idiot decided that websites can't go within 4cm of the edge of the screen?
    There should be a null word, for the question "Is anybody there?" and to see if microphones are on.


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