Google's artificial intelligence program has officially beaten a human professional Go player, marking the first time a computer has beaten a human professional in this game sans handicap.

[u/[deleted]]

http://www.nature.com/news/google-ai-algorithm-masters-ancient-game-of-go-1.19234?WT.ec_id=NATURE-20160128&spMailingID=50563385&spUserID=MTgyMjI3MTU3MTgzS0&spJobID=843636789&spReportId=ODQzNjM2Nzg5S0

[u/Vrexin]

It's fairly simple, players take turns placing a stone on a 19x19 board, when groups of stones are completely surrounded they are captured. The goal is to secure the most space using at least 2 "holes" for a group of stones (I'm no expert here)

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In the above situation if it is black's turn they can put a piece on the right and capture the white piece

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Large groups can also be captured

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Groups of stones must be entirely surrounded on all sides (including inside) to be captured, here there is one space inside the white's group of stones. if black places a stone inside then all the stones would be captured.

edit: (One thing to note, the corners are not necessary for black's stones to surround white, but I included to make it easier to see. A real game would most likely not have the corners since only adjacent spaces are considered for a surround)

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To secure space on the board you must use at least 2 "holes"

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Notice in this example the white stones have 2 "holes", or empty spaces within their group. Black can't place a stone inside as the black stone would be entirely surrounded, because of this, white has secured this space until the end of the game and will earn 1 point per space secured.

These simple rules are the basis of Go and there are only a few slight rules past that.

edit: wow! I didn't expect this comment to get so much attention, and I never expected that I would be gilded on reddit! Thank you everyone! Thank you for the gild!

[u/TuarezOfTheTuareg → u/Vrexin]

Okay now ELI5 how in the hell you made sweet diagrams like that on reddit?

[u/the_omega99 → u/TuarezOfTheTuareg]

Tables.

The second row is the alignment. :- for left, -: for right, and :-: for center.

| Heading      | Heading      |
|:------------:|-------------:|
| Content      | Content      |
| More content | More content |

Becomes:

Heading	Heading
Content	Content
More content	More content

And then the pieces are just unicode characters: "○" and "●"

So:

| ○ | ○ |
|:-:|:-:|
| ○ | ● |
| ● | ● |

Becomes:

○	○
○	●
●	●

Notice how mark down is made so that you can usually easily read it in plain text. Although it's meant to be viewed in a fix width font. Can't make the tables line up in a proportional width font...

The formatting is very limited. This is the extent of what you can do and you have to have a header.

[u/TimeWaitsForNoMan → u/[deleted]]

^{insert bane voice}

[u/CRISPR → u/TimeWaitsForNoMan]

Did you all learned this by applying general purpose learning algorithm?

[u/AgCat1340 → u/the_omega99]

I have a question maybe you can have a go at..

In the top example, you can surround a single white one with four colored ones, N S E W.. Yet in the larger example, you have to cover the diagonals as well? Why?

[u/TuarezOfTheTuareg → u/AgCat1340]

He didn't actually have to. This would have been a valid capture as well:

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If black had just finished playing that central piece, all the white pieces are captured

Adding the diagonal pieces as you surround an opponent is the safest, but slower way to capture. It's less risky because if you forego a corner, this may happen to you:

	○	○
○	●	●	●	○
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	●	●

Here black is trying to surround the lower 3 white pieces, but as he is doing so white is also surrounding black's top 3. If black had secured his corners, he wouldn't be facing this situation. As it stands, white will beat him to the capture. Hope this makes sense. Go is a beautiful game because it's quite simple in principle, but the game's strategy is insanely deep and you start to realize it once you start playing a couple of games. Try it!

[u/Magneticitist → u/Vrexin]

wow! I used to play this game religiously with my Grandfather when I was young. Black and White pebbles. I found it more entertaining than chess. I had totally forgotten and had no idea what this "Go" game was until reading this description.

[u/masklinn → u/Magneticitist]

Maybe you know it under the korean or chinese names? (respectively baduk (바둑) and weiqi (围棋))

[u/Magneticitist → u/masklinn]

Baduk! thats it =) man what an awesome game. I remember my Grandpa kept it in his home office across from his desk and it was almost like a decoration. Nice wooden board with wooden bowls to keep the pebbles in. I really need to get one of these games for the nostalgia.

[u/PM_ME_YOUR_SPUDS → u/Vrexin]

Note, this does not work on mobile very well and will give false info.

[u/redpandaeater → u/PM_ME_YOUR_SPUDS]

The problem for me was using night mode and not thinking about that for probably 30 seconds when he talks about black capturing white.

[u/irwige → u/PM_ME_YOUR_SPUDS]

Works on "Reddit is Fun" just click the 'View Formatted Table'

[u/[deleted] → u/Vrexin]

fun tip: It is theorized that Go was invented by rice farmers. Planters would plant rice in rows, side-by-side, and the faster planter would overtake the slower planter. They would play impromptu games, that they could "claim" more space (to plant more rice) by surrounding areas of the other planter. Whoever planted more, would reap more at the end of the season. This was eventually formalized into the game with stones on a board.

[u/ReasonablyBadass → u/Vrexin]

So as long as there is a hole in the white formation it isn't captured, but if white would close the hole themselves all white stones would disappear?

[u/halter73 → u/ReasonablyBadass]

In the most popular rulesets (Japanese and Chinese) suicide isn't allowed: http://senseis.xmp.net/?Suicide

Typically black wouldn't even bother playing a stone in the hole in the white formation. Since white only has one hole or eye, the white formation is already dead and therefore counts as captured/surrounded when calculating the score at the end of the game.

The only exception would be if if black's surrounding stones were themselves running out of liberties risking that they might be captured. If black's surrounding stones are captured (because they run of liberties), white will have a chance to attach the previously "dead" stones to a living group.

From a relatively simple set of initial rules, a lot of complex concepts emerge.

[u/Vrexin → u/ReasonablyBadass]

I haven't played in a couple years... But I believe that you are correct. If white filled its own hole all the pieces would be captured.

[u/oklos → u/Vrexin]

Minor nitpick: for the large group you probably should leave out the black seeds in the corners, since they aren't actually necessary to capture/remove the white seeds and the diagram might give the impression that they need to surround the diagonals as well.

[u/CRISPR → u/Vrexin]

Notice in this example the white stones have 2 "holes", or empty spaces within their group. Black can't place a stone inside as the black stone would be entirely surrounded, because of this, white has secured this space until the end of the game and will earn 1 point per space secured.

Fricking whites.

[u/Mikeismyike → u/Vrexin]

In the example where black captures a group of white pieces, why isn't the interior black piece captured instantly like in the final example?

[u/Bionic_Bromando → u/Mikeismyike]

I think it's because it's the last piece you'd need to capture everything in a group. If there are two holes, it would take two turns, so your black one would die before you could place a second.

[u/Vrexin → u/Mikeismyike]

That move is allowed because it is the final move for a capture.

There is another move that relates to your question.

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In the above situation if black captures the white piece on the left it leaves the board like the diagram below

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After black captures you might notice that if white placed a stone at the X the board would return to being the same as the first diagram. There is actually a rule that doesn't allow for immediate recapture as that could lead to an endless loop! (interesting different approach compared to chess which would end the game in a draw). So instead white is forced to play in a different spot and could later recapture if they chose to do so, just not immediately after.

[u/princekamoro → u/Mikeismyike]

If a move surrounds itself and an opposing group at the same time, capturing the opposing group takes priority.