Life In 19x19

Let's wait to see more details of the metric actually used

jlt wrote:

mhlepore wrote:The binomial calculation requires that *each* of the N observations be generated with probability P, but we know that some of the moves are trivial, and others are quite complicated.

IMO this doesn't affect the conclusion much.

Sorry to disagree with your opinion: what mhlepore stated is the statistical hypotesis, so it is the precondition to be apply if one's want to use this kind of statistical analysis. Much more than an opinion.
I think that the 98% line of reasoning needs more support and is now far from proven, according to the data provided by the referee team,

Galation

I'd like to raise some attention to a strange move that wasn't mentioned before: e2

I think any strong player knows that g2's purpose is to get sente - you make this exchange and then play away (or you just descend in gote to c2). No pro, and I think no strong amateur, would add e2 immediately. It reduces the aji of the g2 stone (mainly related to d5) and white doesn't really have a good way of saving his 2 stones - he may save them in sente (probably) by just connecting, but that would leave the aji from before.
Now, for a more psychological approach - the biggest single territory that's forming on the board is the white one at the bottom and black is not just ignoring it - he's strengthening it with this weird exchange...

At first, observing the game and rooting for my team, I was happy to see this "sign of weakness", but thinking about this kind of move now, it really feels like a bot-decision when assessing good chances for himself and not caring for some bad exchanges.

As Stanislaw skipped this move in his review, I felt obliged to add this comment.

OferZ wrote:I'd like to raise some attention to a strange move that wasn't mentioned before: e2

I think any strong player knows that g2's purpose is to get sente - you make this exchange and then play away (or you just descend in gote to c2). No pro, and I think no strong amateur, would add e2 immediately. It reduces the aji of the g2 stone (mainly related to d5) and white doesn't really have a good way of saving his 2 stones - he may save them in sente (probably) by just connecting, but that would leave the aji from before.

It is indeed an interesting point to discuss. So is this sequence perhaps a standard for Leela in this joseki continuation - is it the case that if you are playing "Leela 0.11" style, that you learnt to do this kind of move?

OferZ wrote:I'd like to raise some attention to a strange move that wasn't mentioned before: e2

I think any strong player knows that g2's purpose is to get sente - you make this exchange and then play away (or you just descend in gote to c2). No pro, and I think no strong amateur, would add e2 immediately. It reduces the aji of the g2 stone (mainly related to d5) and white doesn't really have a good way of saving his 2 stones - he may save them in sente (probably) by just connecting, but that would leave the aji from before.
Now, for a more psychological approach - the biggest single territory that's forming on the board is the white one at the bottom and black is not just ignoring it - he's strengthening it with this weird exchange...

At first, observing the game and rooting for my team, I was happy to see this "sign of weakness", but thinking about this kind of move now, it really feels like a bot-decision when assessing good chances for himself and not caring for some bad exchanges.

As Stanislaw skipped this move in his review, I felt obliged to add this comment.

Well now I feel ashamed because always did make that exchange And I am 5d. Just looked at the joseki and indeed black does not play that atari..

Bohdan wrote:

OferZ wrote:I'd like to raise some attention to a strange move that wasn't mentioned before: e2

I think any strong player knows that g2's purpose is to get sente - you make this exchange and then play away (or you just descend in gote to c2). No pro, and I think no strong amateur, would add e2 immediately. It reduces the aji of the g2 stone (mainly related to d5) and white doesn't really have a good way of saving his 2 stones - he may save them in sente (probably) by just connecting, but that would leave the aji from before.
Now, for a more psychological approach - the biggest single territory that's forming on the board is the white one at the bottom and black is not just ignoring it - he's strengthening it with this weird exchange...

At first, observing the game and rooting for my team, I was happy to see this "sign of weakness", but thinking about this kind of move now, it really feels like a bot-decision when assessing good chances for himself and not caring for some bad exchanges.

As Stanislaw skipped this move in his review, I felt obliged to add this comment.

Well now I feel ashamed because always did make that exchange And I am 5d. Just looked at the joseki and indeed black does not play that atari..

Well... everyday we learn something new
I'm sure that many other josekis you know much better than most.

But - what was the logic behind that choice? I think that once the player feels like saving the 2 stones he will gain a bit with that exchange. I guess the only positive aspect is that it's no longer possible to save the stones in sente - I suppose that if the cutting stone aji is not very useful it doesn't do much harm...
Still I'd like an answer from you, as it's interesting to know if really some people were taught that that's the way to play the joseki.

Anyway - I tried checking the position with Leela, and it does seem to like this move as well.

In reference to Black's atari at E-02:

OferZ wrote:But - what was the logic behind that choice? I think that once the player feels like saving the 2 stones he will gain a bit with that exchange. I guess the only positive aspect is that it's no longer possible to save the stones in sente - I suppose that if the cutting stone aji is not very useful it doesn't do much harm...

Viewed as a double sente, E-02 gains on average about 2 pts. in the corner. How much does it lose on the bottom side, through the loss of aji? If Black has no designs on the White moyo there, that aji won't be worth much, if anything, and E-02 ought to look reasonable both to humans and to bots. Given Black's game plan, where the fight in the center should strengthen White's bottom side moyo, E-02 makes perfect sense. See the position after for reference. You don't have to read every play out to form the general picture. (Not that I would have formed that plan myself. )

Anyway - I tried checking the position with Leela, and it does seem to like this move as well.

Very interesting.

I might play the e2 atari if I were playing that game. I am aware it's usually not played, but my thinking would be thus. First I don't like that white might play d2, is this sente? Probably not as jumping into the corner and an extension around c7 are kindo miai, but still I don't like white getting either of those in sente to hassle my group. But playing e2 means if he later d2 then c2 is sente atari. Yay, corner safe, a downside is compared to gote block at c2 the endgame is worse, but sente more important. The other downside (apart from lost ko threat) is the g5 wedge loses power. But is that relevant in this game? I think not as I'm unlikely to want to invade the lower side once white has jumped at o6. True it's a 2 point jump so thin, but also r3 is 2 spaces from o3 so m3 doesn't have a clear threat to connect. Maybe I might reduce from the n6 direction in which case a invasion might develop if white aggressively caps and then g5 and the h4 cut after gives some counterattacking potential but that seems too many ifs. If I think I'm leading then kesh the aji and make sure c2 is sente is plausible.

Stanislaw highlighted several instances of Leela liking moves Carlo didn't play and vice versa: here's one I found interesting. After whites o14 attachment (which seems quite a desperate "let's make a mess" and chance to catch up move) Carlo carried out the threat of t14 with the s12 atari and then capture. Leela likes s12 but not capture and wants to answer o14. So why play s12 and not capture, schizophrenic bot foibles? I think not. If black directly answers o14 with natural moves whites plan could be o14, o15, p15, p14, q14, o13, r15, q13, s16. However with the s12 s11 exchange made this sequence doesn't work as black takes 2 stones at the end. That Leela saw this but Carlo didn't suggests to me Carlo was the one playing. Of course it's possible he was using Leela and chose to ignore this suggestion, but if this is your proposition you need better evidence to convict. s12 and then capture is very natural to a human. If we can get move timing information from the game record and see those moves in quick succession that's more evidence for not using Leela.

Edit:
- t14 hanes took 5 seconds.
- s12 cut (deciding to ignore o14 attachment) took 15 seconds.
- t13 capture took 11 seconds.

They both played pretty fast: about half an hour each at this point.

And a diagram for possible white plan. No good if marked stones already played.

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . X . . . . . . . . . . . . . . |
$$ | X X . . . X O . . . . . . . . . . . . |
$$ | . O X X X O . . O X X . X . . . X . . |
$$ | . O O O X O . O . O O X . . . , . 8 . |
$$ | . . . . O X X . . . O . . 1 2 . 6 X . |
$$ | . . . . O O . . . . . . X . 3 4 X O X |
$$ | . O O O X X . . O . . . . 5 . 7 X O . |
$$ | . X . O O X . O . . . . . . . . O B . |
$$ | . . X X X X X X X . . . . . . . O W . |
$$ | . . . , . O . . . , . . . . . , . . . |
$$ | . . O . O . O . X . O . . . . . . . . |
$$ | . . . . . . . . . X X X . . . . O . . |
$$ | . . . . . . O X X O X . . . . . . . . |
$$ | . . . . . . O X O O O X . O . . X . . |
$$ | . . X . . . . O . . . O . . O . . . . |
$$ | . . . X X X O . . , . . . . O X . . . |
$$ | . . X O O X O . . . . . . O X . X . . |
$$ | . . . . X O . O . . . . O O X . . . . |
$$ | . . . . . . O . . . . . O X X . . . . |
$$ ---------------------------------------[/go]

The timing information is clearly available in the original game record

I have no opinion whether there was cheating in this particular game, although in chess a 98 percent agreement between an engine and a player would be considered very strong evidence (even the best chess players in the world who train with computers all the time don't score nearly as high).

However, I was actively playing chess online during the period when commercially-available engines got really strong, and this experience has made me very cynical. Many people are honest and would never consider using an engine to cheat. But a surprising number of people will cheat if they think they can get away with it. Some will cheat stupidly and get caught very easily; others will cheat intelligently and perhaps never be caught. Some amateurs will cheat; so will some professionals.

I am sorry to be so negative, but my experience with chess online has taught me that cheating is much more common than honest people would like to believe, and to maintain the integrity of online play some strong anti-cheating measures will be needed.

Bartleby wrote: although in chess a 98 percent agreement between an engine and a player would be considered very strong evidence (even the best chess players in the world who train with computers all the time don't score nearly as high).

When you talk of agreement with a chess engine do you mean playing the top choice of the engine, playing one of the top 3 choices of the engine (as in this case), or some more complex comparison. I am concerned that by choosing the broader top 3 metric a headline figure of 98% can be quoted (without telling people the typical distribution of non-cheaters) which suggests more guilt to the casual reader than warranted. When comparing to Leela's top choice I got 72% agreement*.

* It may be even lower if you allow Leela to analyse more deeply. Leela starts off analysing moves suggested by its policy network, which has been trained on strong human games, so has a very human-like style (unlike -Zero bots). As it analyses more it may come to prefer moves which the policy network didn't like; AlphaGo's move 37 5th line shoulder hit being a famous example. To give an example from this game : in my first analysis for move 51 l17 was Leela's #1 choice and this is what Carlo played. It is also quite likely what I would play. But if I let Leela analyse for longer l17 becomes the #2 choice and e11 becomes #1. This may well happen with other moves too, so a deeper Leela analysis could see this similarity metric of 72% drop even further.

P.S Another data point: a 1 kyu on reddit got 64% similarity to Leela's top 3 over moves 1-150 of his correspondence game; would be lower over same 50-150 interval as more similarity in opening. Chart: https://i.imgur.com/jMM4EIM.png. Unsurprising that a 1k isn't as good / similar to Leela at middle game than mid dans.

Come on it is not that difficult to get better data on this for Pandanet

They have got lots of games of dan players. Just run a check for the past games and you got a baseline. You can determine how similar an average dan x player plays to a specific engine.

Ok you have to consider some things like bots and such ...

But it is not too difficult.

Speaking in general, not specifically about any person:
If you are cheating you can do it in a few ways, I'd suggest 6 for starters.
Using a single AI assistant
* copy every 1st choice move the AI pops up.
* use the AI's suggestions in difficult situations.
* use the AI's suggestions when they suggest a big shift in winning %.
* use the AI's suggestions for a time when you fall behind.
* use the AI's suggestions when you have no idea how to proceed.
* simply observe the AI's suggestions before moving, but decide what to play by yourself.
You can also use multiple AI, which may complicate things further.
Which can be detected easily? Which can be detected with enough data?

The investigation took about 5 months, I imagine they looked at this kind of stuff already. I wonder what they found.
I'd want to see performance ratings in online tournaments vs offline tournaments for any suspect.
A damn funky mother of a readout showing the goodness of each move during the games would also be mandatory for a top rate detective analysis script.

In another 5 months, I expect to see both

for these kind of problems you have to use a ...

... deep learning network