0832: "Tic-Tac-Toe"

[GuusRob]

I must say I looked at it for five minutes, not even reading the text or alt-text, because it just looked... pretty.
Now this is something that would have been called brilliant if some art student made it up, seriously. Lucky that Randall is not an art student.

It also kind of reminds me of anarchistic tic-tac-toe, what I just to do with friends in school (and sometimes now at the university, though rarely). As you may have guessed, we discarded all the rules and just (most often) started with the X and O's, ending with (par example) drawing unicorns on the floor with chalk or building a tower of books. Nobody could lose or win, so good times for all to be had.

[Fantasmageekic]

Coincidentally, War Games is the movie I had planned for our "family fun night" viewing this evening.

[thescientist]

Colour-blind people who complain about parts of the strip being red: Seriously? Adjust the colour settings on your damn screens. the red-green variety can still see blue, right?

yeah, cos i love having a false-colour monitor

interesting to note that it is easier to see on my home monitor that I have adjusted to suit my vision better (though still difficult) than it was on my work monitor. I've tried to keep it true to what I actually see though, if I'm making any sense with that statement. And I was glad to see I'm not the only one who found it hard to see and then someone else pointed out the colour vision study Randall did...

[snowyowl]

Colour-blind people who complain about parts of the strip being red: Seriously? Adjust the colour settings on your damn screens. the red-green variety can still see blue, right?

There's not even any blue in this comic. The only risk for colour-blind people is if they can't see the difference between red and black. And I don't even know if that form of colour-blindness exists. (If it does, I'm sorry for offending any xkcd-reading red-black colourblinds out there, and I'll make an animated GIF version of this comic with flashing colours instead of red.)

[nealh]

xkcd is a information representation genius.
Someone please create a zoomable seadragon / google-maps like view of this... "fractals" ftw!

Agreed. After movie narratives http://xkcd.com/657/ and gravity wells http://xkcd.com/681/, Randall certainly aced his data representation course, aifinkso.

[uncivlengr]

I must say I looked at it for five minutes, not even reading the text or alt-text, because it just looked... pretty.
Now this is something that would have been called brilliant if some art student made it up, seriously. Lucky that Randall is not an art student.

Exactly - the notion that you can produce a visually engaging fractal from something as mundane as TicTacToe strategy is what I see as the highlight of this comic. Anyone that's looking at this as a cheat-sheet/walkthrough for players to use is missing the point.

It's much more interesting than the "all possible games" fractal in the link on the first page, too.

[dp2]

A number of people already pointed out that the ingenuity lies in the representation of the data, not the data itself, and that is what they are praising. I don't think Randall deserves credit for the representation, and the optimal strategy of Tic-tac-toe itself is not very interesting.

The comic is still cool, and to each their own and such; I just don't think the comic is as impressively ingenious if you are familiar with the original diagram.

Now that that's been pointed out, yeah, it's disappointing. I would eat my words but it seems my mouth is too full of balls. Right, From Canada?

I still tend to be impressed with the graph-based comics.

[BlueNight]

Am I the only one who always looked at tic-tac-toe Ender-style? No matter where the X went, I always mentally oriented it to the top-left or top-middle of the board. Looking at it this way, there are only three starting moves - corner, center, and edge. The board can be mirrored mentally, as well as rotated to fit your viewpoint. Because of the simple 3x3 nature of tic-tac-toe, and how much of it is based on perspective, it makes a significant portion of this map redundant.

I like it, it's interesting, but redundant.

I think that perspective is built in.

And I remember the day I learned to always take corner square as my first move, as X or O. I completely dominated... and nobody else wanted to play with me.

[shoo]

Colour-blind people who complain about parts of the strip being red: Seriously? Adjust the colour settings on your damn screens. the red-green variety can still see blue, right?

There's not even any blue in this comic. The only risk for colour-blind people is if they can't see the difference between red and black. And I don't even know if that form of colour-blindness exists. (If it does, I'm sorry for offending any xkcd-reading red-black colourblinds out there, and I'll make an animated GIF version of this comic with flashing colours instead of red.)

I think you misunderstand how color blindness works.

If you are red-green color blind, as I am, you will have difficulty distinguishing the color red, but you will not have difficulty seeing darkness. So, since the dark red that his being used is close in darkness to the black, it is difficult to distinguish the red, which appears to be just dark, from the black, which also appears to be just dark.

To give you an idea how this works, try taking that comic and putting it in greyscale. No, that's not necessarily actually how color-blind people see things, but the analogy works. See if you can distinguish the lines easily then.

I have to concentrate pretty damn hard to figure out if a given line is red or black in this comic. Presumably, normal sighted people would pick this up instantly.

[darthbyu]

I can only assume that the working definition of "optimal" in the comic is maximizing the likelihood of winning with the assumption that all of your opponent's possible moves are equally likely. Or, equivalently, giving your opponent as many ways to screw up as possible (which fits well with the title-text).

Those who espouse the center-first strategy are trying to anticipate their opponent's moves, meaning that they weight moves differently. If your weights are accurate, you will probably do better than "optimal," but if not you'll probably do worse. Of course, if your opponent knows your strategy, then he can use it against you. I'd guess that if each player knew the other's strategy, it would converge on the solution in the comic, just like paper-rock-scissors converges on complete randomness.

I wonder what strategy that matchbox AI would learn after playing against a representative sample of the (human) population.

[aegiswings]

Please fix the colors!!

It is impossible for anyone with even mild protanomaly (a kind of red-green colorblindness) to understand this chart. Up to 8% of all American men won't be able to make any sense of it (myself included). In fact, I didn't even know there was "red" in the chart until I read the caption. If you keep the "red" at least make the red lines thicker or something. I'd really actually like to try it out and see how it works.

[huy]

Man, if Joshua could have kept such a map in memory back then...

[tgeek]

Fucking fractals, how do they work?

[Glenn Magus Harvey]

EPIC. WIN. This comic is EPIC WIN.

^ Okay, except possibly the colors. Maybe make them blue or something? I don't know much about color-blindness...

[jpers36]

Hasn't anyone noticed that this is wrong? I haven't looked at the best moves for O bit, but the best move for X is always to go in the middle. Also on tracking through a game I got stumped until I realised that a cross that should be red was actually black.

It's not wrong. Assuming perfect play from O, both middle X and corner X are tie games for X and are thus equally valid. And assuming anything less than perfect play from your opponent leads to non-optimal decisions in games with perfect information.

[aegiswings]

Tic Tac Toe with red changed to blue

For those of us who are colorblind.

[Tempoz]

In the X chart the block in the lower left, then middle top, then middle is wrong. It showed that the O was in the middle bottom, when it should be in the middle.

[kslays]

Here's a puzzle for you all. In "toe-tac-tic", your objective is to force the other player to get three in a row. What is the best strategy (and if you Google it, you'll spoil the fun for yourself)?

[Vehemence]

Am I the only one who always looked at tic-tac-toe Ender-style? No matter where the X went, I always mentally oriented it to the top-left or top-middle of the board. Looking at it this way, there are only three starting moves - corner, center, and edge. The board can be mirrored mentally, as well as rotated to fit your viewpoint. Because of the simple 3x3 nature of tic-tac-toe, and how much of it is based on perspective, it makes a significant portion of this map redundant.

I like it, it's interesting, but redundant.

I think that perspective is built in.

And I remember the day I learned to always take corner square as my first move, as X or O. I completely dominated... and nobody else wanted to play with me.

It isn't. There are an awful lot of repeat squares if you rotate or mirror the board. I'm too busy at the moment to count out or do the math on how many redundant scenarios there are, but considering that all first moves can be reduced to the three I mentioned just by rotation, I'd venture it's somewhere around 2/3 of them by this method alone.

[neoliminal]

When I was a kid my mother and I would play tic-tac-toe in the car. We didn't have paper and pencil so we would just say numbers. I would say 5, she would say 9, I would say 3... etc.

What I came to realize only years later was that we had never defined what order the boxes were in:

Code: Select all

123
456
789

147
258
369


And I asked my mother to draw it for me.

She had been playing the lower version and I the upper version, basically inversed, but that didn't affect the result of the game. This had a profound effect on my world view.

[butchler]

I tried creating a version with thicker lines for all of the red X's and O's. It's kind of really messy, but does this help at all for all the colorblind peeps out there?

[SEE]

You're wrong. Checkers has been solved, draughts has not.

Draughts and checkers are the same game, just as football and soccer are.

Anyway, anybody want to play a game of Fifteen? Players alternately select numbers from the pool of 1-9. Whomever first gets exactly three numbers that add up to 15 wins.

Spoiler:

Which is to say, it's the same game as Tic-Tac-Toe, played on the following magic square:
6 1 8
7 5 3
2 9 4

[RockoTDF]

How is this NOT a thinly-veiled insult of the intelligence of the readers? He's basically saying "Since you could never figure this out yourself, I compiled this genius chart for you." And yet you still fellate Randall, saying how interesting/useful/whatever it is. I've known that tic-tac-toe was unbeatable with the advantage to the person with the first move since ten years old, at the very latest. It never made sense to my why it was so popular given that fact. Either way, isn't the optimal move always ridiculously obvious?

People like you are why I hardly ever get on the fora anymore. Because no matter what Randall does, he is offending or insulting someone. I'm not a hardcore fanboy, but your post is arrogant and ridiculous.

Granted, if you were accusing him of plagiarism (or some degree of it) like other posters, you'd have some legitimacy.

[Volbla]

She had been playing the lower version and I the upper version, basically inversed, but that didn't affect the result of the game. This had a profound effect on my world view.

It's actually the same thing, just viewed from different ways.

http://i154.photobucket.com/albums/s246/Volbla/perspective.png

In Sweden this game is called bum chess.

[Mekmek]

Alt Text: The only winning move is to play, perfectly, waiting for your opponent to make a mistake.

A strange game... I mean strange comic, I mean... Wait what?! That's not a movie quote!

[RMo]

Alas, I am colorblind, and this map is useless. (I can't tell the difference between thin red and black lines. Blue probably would have been better. Some day, I shall Photoshop this map to my advantage...)

[aegiswings]

Alas, I am colorblind, and this map is useless. (I can't tell the difference between thin red and black lines. Blue probably would have been better. Some day, I shall Photoshop this map to my advantage...)

I did exactly that, see my post above.

[jps]

I scanned through and didn't see someone else mention this, but I am thinking that the "X" located at:

Middle -> Bottom-Middle -> Upper-Right -> Bottom-Left

... should be red?
(There are no other red X's in that "upper right" box for instance, and from what I can tell, that particular X was the "suggested" location.)

Thanks. Love the comic. Been reading since before 200.

[More2Life]

Great Scott! Good job!

[Cool Username]

So, let's see here. It's full of mistakes, it's shoddily drawn, it's blatant poster-bait, and most of all it's not original in the slightest.

Yep, this is a terrible comic.

[DoubleMike]

I tried using this for about five minutes, and I found eight mistakes in the "Map for X". Seriously?

[rhhardin]

Number of completed draws for the general game on a nXk grid
http://oeis.org/A181029

[jbaber]

I didn't mean he quoted incorrectly. I meant the only right move he gave was "incorrect". The "correct" answer is Joshua's. It's a joke. Looking at this forum, I can see things aren't so light-hearted around here...

[SirMustapha]

For the love of God please click one of the links in my sig so I can someday move out of my mom's basement

fixt

That's about the fourth of fifth time I've read that rebuff here. Really, are you people that original? Must be reading way too much xkcd, then.

You could be living your life, accepting that no one (not even webcomic artists) are perfect and make mistakes and are just people, happy as could be, being thankful that you are occasionally provided with some free entertainment before you get ready to face the day...

IT'S FREE, THEREFORE I SHOULD LOVE IT!

Instead, you opt to flaunt some meaningless sense of superiority in an effort to condescend to and insult someone you don't know (and hopefully will never meet -- the indignity!).

There's no sense of superiority being flaunted here... just Randall's inferiority being stated loud and clear. He has his (very loud and buzzy) fans, and so he has his detractors, and the balance of the world is maintained.

For what? Personal validation?

No. "RANDALL GET OUT OF MY HEAD" is personal validation. Criticism is just criticism.

Just because you can?

Welcome to the Internet.

Even then... why not target the truly deserving?

For me, Randall is truly deserving. Could you maybe please accept this opinion and stop being an annoying stubborn brat?

If you make the effort to think positively, I think you'd be surprised at how much more you enjoy life. It really won't hurt you at all, I promise.

You condemn ME for criticising someone "I don't even know", and you do EXACTLY THE SAME TO ME. Wow, such kind of hypocrisy is hard to come by. In case you're not aware, I'm a very well satisfied and happy person. Even though xkcd takes a negligible slice of my time, I have to say I value that time, you know why? Because I like to exercise my freedom of speech. And if everyone shared your view that "I SHOULDN'T BE HERE I SHOULD BE GETTING LAID LOL", I would have been banned a long, long time ago. But I haven't, and that's probably because many people who plainly disagree with me ignore me (though once in a while I bump into people who can actually articulate counter-opinions here, which is always nice). Maybe you should do the same? Or maybe YOU have your personal issues and your own negativity to spew? Maybe you should look at yourself instead of trying to fix the others first?

[dsoodak]

When I was about 8 years old, someone bet me they could win if they went first and I chose a side square. I'd long since given up finding an actual winning strategy for the game (even for the first player) so I agreed.
And he won...
Later, I drew out all the possible games to figure out how he did it (I eliminated games with mirror and/or rotational symmetry, so my diagram wasn't anywhere near as large).

Below is the winning strategy if you go first and the other person chooses a side instead of a corner square for their first move:

Code: Select all

___  X__  X_X  X_X  XXX
_XO  _XO  _XO  _XO  _XO
___  __O  __O  O_O  O_O


Dustin

[fimzo]

...I came in to suggest he make a diagram like this for chess (obviously not seriously). Wow, I didn't expect such an outburst, although I suppose that I could have anticipated it if a few things had occurred to me. Arguments like these reason I barely post on xkcd.
On an unrelated note, I realized that many people join xkcd to make a post regarding a specific comic, usually regarding the nature of the comic. (Example this comic/colorblind people). Therefore, if Randall made controversial comics that people would want to object, the xkcd forums would grow rapidly! (That wasn't serious either, by the way.)

[BytEfLUSh]

Is this better for colorblind people?

http://www.byteflush.com/tic_tac_toe_byte.gif

[Mazuku]

And to think that all I ever did when I played tic-tac-toe was play, not to win but not to lose and if the other player did something stupid, you take advantage and win that way, simple really.

[reminiscence-tbp]

Awesome comic as usual.

May I recommend the image be uploaded in vector format, such as .svg? That way, it'll look clean even looking at the inner most moves when playing circle.

[thescientist]

both the colourblind friendly versions posted are indeed more colourblind friendly

could appreciate it now thanks peeps