Checkers Solved, Unbeatable Database Created
tgeller writes "My story on the Nature site announced that a team of computer scientists at the University of Alberta has solved checkers. From the game's 500 billion billion positions (5 * 10^20), 'Chinook' has determined which 100,000 billion (10^14) are needed for their proof, and run through all relevant decision trees. They've set up a site where you can see the proof, traverse the logic, and play their unbeatable automaton. '[Jonathan] Schaeffer notes that his research has implications beyond the checkers board. The same algorithms his team writes to solve games could be helpful in searching other databases, such as vast lists of biological information because, as he says, "At the core, they both reduce to the same fundamental problem: large, compressed data sets that have to be accessed quickly."'"
Wow. Reminds me of how awesome I thought I was when I was 7 years old and I solved Tic Tac Toe.
...ever since the swelling of Chess's "opening book" began. They randomise starting back-rank positions now in some tournaments, to stave off the eventual "book death" that has already conquered checkers.
(rot13) rpbzbab@tznvy.pbz
Holy crap. .
If you are about to mod me down, keep in mind that this post was most likely sarcastic.
--- Often in error; never in doubt!
Now, far be it from me to criticize the research of a group that can manage to convince someone to give them a grant to play checkers with a computer all day, but their "proof" on that site is a little suspect.
When I click on the proof, all I get is a Java error saying "Unable to connect to server". While the inability to connect to the Checkers server may make it "Unbeatable" in a Wargames-esque "the only way to win is not to play" kind of way, it's kind of a cop-out.
So all we have to do to crash the eventual skynet is move in a direction that isn't diagonal? This is going to be easy.
Since Go always comes up in these discussions, I'll take this opportunity to point those curious about the game to some places to learn more about it:
http://playgo.to/interactive/, learn how to play the game in an interactive fashion.
http://361points.com/atarigo/, play "capture" Go against a simple computer opponent.
http://www.gokgs.com/, after you've learned the rules, play against others online worldwide.
http://www.godiscussions.com/, have more questions about the game? Ask them on this discussion board devoted to the game.
~ roscivs
Also, I've heard before that "it takes longer to learn to play checkers at the master level than it does chess. What checkers lacks in breadth, it makes up in precision and finality." I realize that puts me at risk of being modded as flamebait but I wonder if any other Slashdot reader can confirm or contest that.
My work here is dung.
RTFA: 10^46.
Right. So, is it a win for the first or the second player? Would be nice to mention somewhere.
for(int i=60;i>0;i++) was the check they did to make sure Chinook only looked ahead sixty moves and didn't go over it's time limit in one of it's first challenges against a top human player. And yes that's a bug, lost the first game because of it. I was taking an intro to logic and data structures course from Dr. Schafer at the time.
Free as in "the Truth shall set you..."
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
the only winning move is not to play...
http://games.cs.ualberta.ca/~chinook/cgi-bin/statu s.cgi
GAME 17:
Opponent: Cmdr Taco (cmdrtaco@slashdot.org)
Chinook color: White
Level: Novice
Move number: 3
Game analysis: Chinook has a small advantage.
It's a very sad book in many ways- there was a lot of tension between certain members of the team and you realized that professional checkers was dying rapidly. Tinsley and Schaffer set up a world championship rematch between them (Tinsely won the first one) and Tinsely pulled out after six games saying he felt ill. He checked himself into the hospital, was diagnosed with some aggressive form of cancer and died a few months later. Schaeffer basically retired Chinook from human tournaments since nobody else was even remotely close to Tinsley.
It didn't make many headlines because everyone knows checkers is easy. Except that they are wrong- it's not.
"Seven Deadly Sins? I thought it was a to-do list!"
If you're going first, put your mark in the corner. Almost regardless of what your opponent does, put your next mark in an adjacent corner. He'll now have to block you, and then you put your third mark in yet another corner, and voila, you have 2 winning moves.
The only defense against it is to take the middle square with your first move and then block whatever side X tries to take with your second, and then X has to block your row with his third. That ends the game in a draw.
The only winning move going second is to play for a draw. You won't win unless your opponent makes a mistake.
If I knew the wedgies I gave you back in 6th grade would have resulted in this . . . I might have taken a moments pause.
you didn't answer the question. How many gazillion?
-1 not first post
For non-Albertans... a Chinook wind is some hot air the blows down the mountains and melts the winter snow for a week or so.
http://en.wikipedia.org/wiki/Chinook_wind
So it an analogy for a bright new idea -- like a lite up light bulb.
Therefore there are a zillion things called "Chinook" in Alberta.
So what happens if one automaton plays another? Does the universe implode in some kind of horrible checkers armageddon?
The easiest way to keep "dumb" code from killing us is not to program them to do so. They could mutate their code and decide to kill us anyway, but at that point, they become "smart".
The day an automaton is "unbeatable" is the day it's 500ft tall and shoots nuclear rockets from its fingertips. I think I know a relatively easy way to beat this checkers program.
I think it depends; how many Brazilians are in a gazillion?
42
Violence is the last refuge of the incompetent. Polar Scope Align for iOS
This type of proof is not the same as "your checkers set comes with a handheld database reader to show you the solution of the position you are in" - because it's NOT about 'average players making mistakes'.
They went for the proof of the math behind the game. This article will also be a good flash answer against the wailers who say "but there are 500 billion billion *possible* positions in the game..."
The answer: only a small portion of them *matter*.
Here's the basic chain logic.
"All endgames of 8 pieces or less with a 2 checker advantage are wins except the following known cases... (see appendix.)"
Therefore, any time you can reach that conclusive endgame table, *all further deviations fail to matter*. It matters not that you are an 'average player who played something else'. The remainder of your game became theoretically irrelevant.
What Schafer and team banked on (and Drew) was that the quantity of Theoretically Critical Positions is far smaller than the Possible Positions. At the Master level of both checkers and chess, the results of games after mistakes are actually less important. Someone else also mentioned that it is even harder to turn a checkers game around than a chess game.
My first Journal Entry ever, in 8 years! http://slashdot.org/journal/365947/aphelion-scifi-fantasy-horror-poetry-webzine
Hardly. The checkers program has no degree of intelligence whatsoever, it's just a gigantic brute force "tree" of board positions.
It is no smarter than a choose-your-own-adventure paperback with the "good" endings already mapped out.
One can get much of the overall story online here.
Ok, for other english impared people wondering what is checkers, it is the US name for game of draughts. If you follow that link, you'll instantly recognize the board :)
Of course, as a brazilian, I had no idea people played that on a 10x10 board around the world. Too bad they can't reuse the chess board :)
Rethinking email
HAKMEM item 93 is solved. Back in 1972 when HAKMEM was written, the AI Lab folks estimated a year or so of computer time then, I'm guessing, given how long has passed, that this was a bit optimistic.
I'm a nature photographer.
Jonathan Schaeffer 's book about the development of Chinook (from 1997):
S upremacy/dp/0387949305
http://www.amazon.com/One-Jump-Ahead-Challenging-
Includes the details of the Tinsley matches and Tinsley's untimely death. Interesting for people interested in the effects of technology on human societies, as well as some of the technical aspects of the program (as it was in 1997).
How many gazillion?
10 ^ (46 - log(1 gazillion))
I did my undergraduate at the U of A, and had the pleasure of being a number of Jonathan Schaeffer's classes. The man is a gifted professor, and rather quirky on top of that.
..
One day, we were learning about the "Dining Philosopher" problem. The problem is about 3 philosophers that have to acquire two (shared) utensils on either side of them before they can eat the food in front of them. Those of you familiar with the problem should understand
Anyway, he came in with a pot of spaghetti, forks, and plates. He actually had some students sit down and go through the algorithm. When the first one took a bite off the plate, he asked "Pretty Good, huh?" (of course the student agreed). He also threw some spaghetti against the wall to prove that it was well cooked.
So, after the first student went through the algorithm and used the fork, you can imagine the grimace from the second student that had to use the same shared fork as the first student..
hah! Still makes me laugh.
I won't ever forget about acquiring mutexes in the correct order, however.
f u cn rd ths, u r prbbly a lsy spllr.
Oh yeah, not that complicated, until you consider that in the USA a billion is a thousand million, but in most of the world it is a million million. Or that a sextillion is derived from prefix "sex" which means six, (as in a sextet of ale) but is actually a one followed by 21 zeros.
A septillion (from the word for seven) contains 24 zeros.
So what you may ask is a one followed by 22 naughts? 10 sextillion. A one followed by 23 naughts? 100 sextillion. And yet instead of a one followed by 24 naughts being 1000 sextillion, it is all of a sudden a septillion, even though it has nothing whatsoever to do with the number seven.
I don't even know why I care about all of this. I got to this thread late and the chances of anyone reading my post in the developers section of Slashdot are next to zero. Of course next to zero would be one and minus one. Oh gawd, don't get me started on that....
If the pattern goes 9am, 10am, 11am, why isn't noon 12am?
x is the beginning part of the word, e.g. septillion = 1000^(7+1)
See http://en.wikipedia.org/wiki/Billion and http://en.wikipedia.org/wiki/Long_and_short_scales