
Crazy Stone computer Go program defeats Ishida Yoshio 9 dan with 4 stones - awwducks
http://gogameguru.com/crazy-stone-computer-go-ishida-yoshio-4-stones/
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valarauca1
To put in more westernized chess terms, this would be like beating a 2100Elo
master without bishops. Yoshio is a professional and very skilled, but he
hasn't won a major tourniquet since 1989. Really not an achievement, its nice
to see Computer Go advancing.

A 4 stone handicap between master's is massive. The difference between a 9d
(dan) and 1d isn't actually 8 stones. With an 8 stone handicap a 1d will play
a 9d off the board (provided both are profession dans not amateur). Source
[http://www.amazon.com/Kages-Secret-Chronicles-Handicap-
Go/dp...](http://www.amazon.com/Kages-Secret-Chronicles-Handicap-
Go/dp/0870403869)

Generally I would say that this should put it around US 2-4d (for US Go
Association, or KGS online). Maybe 2k-1d in professional amateur circles. I
doubt it work warrant a 1-3p 'professional ranking'.

~~~
NhanH
I think it's actually a pretty big deal than you're saying. Firstly, Yoshio
was one of the strongest player in the 1970s. Nowadays, despite not being as
strong as he was, I wouldn't say he's equivalent to 2100Elo master. If you
assume that the top player is 2800, a +700 difference mean something like
.9999 probability for the top player to win against Yoshio (which practically
means always). I doubt that would be the case. It's more likely that a winrate
from .66 to ~.85 to be more appropriate. In other word, Yoshio would be
~2600ish ELO. That would still be an underestimate of Yoshio's strength imo.

Professional dan denotes past achievements, not playing strength. Young 1p is
actually more likely to be about half a stone to a stone stronger than some
older pros.

It's fairly hard to quantify how strong 9d KGS or AGA are, since there are too
fews of them. But if 9d KGS is ~1 stones weaker than the pro, add on 3 more
stones and Crazy Stone would be ~ 5d-6d KGS, which would be 95-98% percentile
or more! That would make the computer about ~2100-2300 Elo for chess. Correct
me if I'm wrong, but 10 years ago, no go program would have even come close to
a mid rank kyu players.

Sorry, I know that the ranges given in the post are quite broad and might look
silly, it's just hard to make any direct comparison between the system

~~~
hyperpape
I think .66 is substantially too low. Iyama Yuta is well over 50% against any
professional in Japan, and while Ishida is still competitive in Japan, he's
not a title contender anymore. So I'd wager that Iyama is at least a 66%
favorite against Ishida, and Iyama is himself not 50-50 against the absolute
top players (40-60 perhaps, maybe worse).

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thinkpad20
Combinatorically, Go is considered pretty much the most complex game in
existence, and computer go programs have been historically weak, so this seems
to be quite an achievement (despite that it was against 4-stone-handicapped
master passed his prime).

One thing I wonder, though, if computers ever catch up to humans at Go, could
we simply expand the board size a few spaces, thus dramatically increasing the
problem space and setting computers back a while? I guess that would depend on
what kind of techniques were being used by the computers to solve the games.

~~~
baddox
> Combinatorically, Go is considered pretty much the most complex game in
> existence

Is that considering "game" to include only traditional turn-based board games?
Presumably it would be trivial to make a video game that's vastly more complex
(at least in terms of tree or state space complexity) than Go. Any real-time
strategy game should quality.

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MichaelGG
Are top RTS games like Starcraft hard for AI? I know the default AI isn't
strong, but is Starcraft in theory difficult to trounce humans? I spoke to an
ex-pro player and he asserted AI could never get close, but I don't see why.
It seems like being able to do precise calculations and a near infinite APM
could be a significant advantage.

~~~
T-hawk
What makes AI difficult in these games is pattern recognition of higher level
strategic abstractions. A human player can recognize that placing a Go stone
or a Terran command center projects some power in regions around that spot.
The human can use intuitive pattern matching to assess when he has a superior
force in an area and can push to a decisive tactical victory, even if the
human isn't quantifying every move in precise terms. An AI must quantify every
bit of power projection somehow, which becomes impossible with present
computing resources in games whose possible state space quickly explodes into
10^10 or more possibilities.

It's actually a similar problem to computer vision. Identifying a battle front
from the current state of a war game and recognizing the tactical
possibilities is similar to edge detection in a photograph and recognizing
objects. Humans do that essentially with highly parallel computations and
lookups by billions of neurons. Until we get billion-core CPUs and billion-
ported RAM, AIs will not have the same capability.

Source: I've done some development on AI for Civilization. It sits somewhere
between Go and Starcraft in AI capabilities. Civilization is turn-based like
Go, but the state space explodes far more quickly like Starcraft when you have
100 units which can each make a dozen moves in 100! different orders on a
turn. (In Civ, the order on which units act each turn is extremely important,
where workers lay down railroads for other units to move, or where you attack
a city with artillery before the ground pounders.)

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mark_l_watson
Nice! I spent a lot of free time in the late 1970s and early 1980s working on
my Go playing program Honninbo Warrior (played poorly, but was the first
commercial Go playing product).

The new Monte Carlo search technique (used by Crazy Stone) basically blows all
previous approaches out of the water. I bought the "Championship Go" app for
my android phone, it uses Monte Carlo, and plays well.

~~~
gcp
Monte Carlo for Go was known for a long time. It wasn't until someone (not-so-
coincidentally, the author of Crazy Stone) figured out a way to combine it
with tree search and published his research, that performance began to
skyrocket.

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sp332
A note from near the bottom:

 _For the benefit of readers who aren’t necessarily Go players, a four stone
handicap means that black (the computer) was allowed to place four stones on
the board before white (Ishida) made any moves. This may sound like a lot but,
while it is a significant handicap, it’s not really as big as it sounds._

~~~
T-hawk
Would it be accurate to say those 4 stones are about equivalent to one pawn in
chess?

As a back-of-the-envelope calculation, one pawn is 1/43 of your starting
material in chess if the king is included as a four-point fighting piece. Four
stones in Go comes to 1/45 of your expected endgame material as half of a
19x19 board.

~~~
CocaKoala
It's hard to make a comparison like that because Go and Chess operate on
fundamentally different models. Chess is about capturing a specific piece and
putting your opponent in a position where they have no options but to lose; to
that end, it's a war of attrition where players slowly lose resources until
the game is over (note that I do not play chess at any significant level).

In contrast, Go is about capturing territory by fencing it in. Placing four
stones on the board is like placing four free fenceposts; you can't really
call it a tangible resource like a pawn, but it gives you more of a structure
and gives you some influence over the rest of the board.

It's possible to remove resources from your opponent in go, since you can
surround pieces and capture them. But it's not really an attrition thing like
in chess; it's more about territory and control.

Trying to make it a numbers game and saying "four stones is 1/45 of your
expected endgame material" isn't really relevant to go, because the position
of the stones matters so much more than the number. If you have four more
pawns than your opponent in a game of chess, that's pretty clearly an
advantage; if you have four stones in a totally useless area of the board, or
four stones in a really useless configuration, then they're not helpful at
all.

~~~
gcp
_It 's hard to make a comparison like that because Go and Chess operate on
fundamentally different models_

It is very easy. The nature of the game is completely irrelevant. The question
is what expectation of winning rate a 4 stone advantage gives to a Go player.
For middle ranks, one stone is about 100 ELO-equivalent, or 64% winning rate.
(I think it's closer at top dan ranks, would have to look up the statistics).
4 Stones is about 92% chance of winning between equal players.

The equivalent in chess is slightly more than 4 pawns advantage, or about a
minor piece.

~~~
CocaKoala
I've read four different versions of the comparison you're describing as "very
easy" (four pieces, four pawns, two bishops, a minor piece), so you'll forgive
me if I don't find your statement very convincing given the lack of consensus?

~~~
gcp
You'll notice they didn't support their arguments - they were just guessing.

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throwaway5752
My limited understanding of go is that the stone placement confers position
and tempo, too, which would be undercounted looking at it purely from points.

~~~
gcp
Points (which are a game specific metric) have absolutely no relation to
anything I posted. I didn't even mention them at all! It looks purely at game
outcomes given the initial starting conditions.

~~~
T-hawk
Yes, you've got the right answer. Forget material and point comparisons which
don't really port between the games. The winning percentage conferred by the
handicap is what matters.

Four stones in Go sounds like a lot less than four pawns in chess, but if
that's what the math says by each resulting in the same winning percentage,
then the equivalency is true.

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ChuckMcM
Wow, I was not aware that Go programs had gotten this good. That is excellent
news. No a bunch of new papers to add to my list to read.

~~~
visarga
Crazy Stone got 4 stones handicap, I think. It wasn't a level playing field
yet.

~~~
dragontamer
A few years ago, it was impossible for a computer to beat a pro with a 9-stone
handicap.

This is a major advancement for Go AI, no matter how you slice it.

~~~
awwducks
Absolutely. A few years ago, even I, a low amateur dan, was able to beat the
strongest AIs with the computer taking 9 stones.

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javanix
On a semi-unrelated note, is there a decent English-speaking online Go
community anywhere?

I would like to try my hand at playing but I can't find anything along the
lines of FICS, or even a decent-looking client for Android.

~~~
hyperpape
www.gokgs.com is the server that's probably biggest in the English speaking
world. The desktop client is Java based, there is an Android client, and we're
waiting for an HTML client (it's in closed Alpha). There are several other
servers that cater more to Asian players, but you can certainly play on them.

There is also online-go.com, which is web-based. It has real-time games, but
the majority of games on the server are correspondance.

Resources: senseis.xmp.net (an old wiki that has lots of content, but few
active contributors), and lifein19x19.com/forum, a forum dedicated to Go.

~~~
mVChr
I didn't know about the KGS HTML client. Either I should hurry up with my
side-project or abandon it, as that's exactly what I'm building (but obviously
without the already established KGS user base).

~~~
hyperpape
There are sporadic reports about development on the KGS account for Google+.

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famousactress
Damnit! I'd finally gotten used to the disappointment that kept coming from
expecting to click through a link and read about a game but instead landing in
an article about a programming language.

Now I just feel like I'm being punk'd.

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awwducks
Here is Crazy Stone's account on KGS (a reasonably popular go server).

[http://www.gokgs.com/graphPage.jsp?user=crazystone](http://www.gokgs.com/graphPage.jsp?user=crazystone)

That AI is 6d on KGS.

~~~
mVChr
And just for a comparison, here's the graph for a popular long-time KGS
player, currently ranked #79 in the KGS top 100 players:
[http://www.gokgs.com/graphPage.jsp?user=twoeye](http://www.gokgs.com/graphPage.jsp?user=twoeye)

CrazyStone isn't too far behind.

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cjbprime
If anyone would like more background, I have a previous blog post --
"Computers are very good at the game of Go":

[http://blog.printf.net/articles/2012/02/23/computers-are-
ver...](http://blog.printf.net/articles/2012/02/23/computers-are-very-good-at-
the-game-of-go/)

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username42
I can play go (I am 1kyu). The game against crazy stones is really impressive.
I feel that Ishida played at his best level against crazy stones and that
crazy stones would not have won if it hasn't found the marvellous move 52. In
the game against zen, I feel the level was lower.

The handicap of 4 stones seems to be very accurate. This means that crazy
stones has the same level than top amateur players.

Generally, in Go, fast games are an advantage for computer. I wonder what
would give a slower game.

congratulation to crazy stones.

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apw
For those looking for some details behind how Crazy Stone actually works, this
set of slides may help:

[http://remi.coulom.free.fr/JFFoS/JFFoS.pdf](http://remi.coulom.free.fr/JFFoS/JFFoS.pdf)

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mcv
Cool. Computer go has come a long way since the days I still played regularly.
Back then I could still defeat the strongest go computer. There's clearly no
chance of that ever happening again.

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aalpbalkan
Took me a while to realize the program actually isn't written in Go.

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unix-dude
Someone should implement this in Go :)

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89vision
confusing title, I was expecting golang

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apetresc
Now you know how all of us Go players have been feeling for the last four
years.

~~~
gcp
The dread of trying to Google anything based on the presence of the term "go".

