It sounds relevant, but I understand nothing of what you want to say in this quotation. Please explain what you mean.

Why in statistics? Why only in statistics? What value? What, for your intention, is a forced move? What is the middle game and why does it not run in parallel from the game start to the game end? What research do you want to see?

Fair enough, that's why I wrote suspicion/conclusion as I wasn't sure how far along the scale just the histograms put you.

Your not-much-red histogram of the European pro is interesting, and I think you should include it in your report: at the moment your case suffers from not having control groups (of other players, having live games of Carlo is a good start) so it's easy to criticise with "maybe other innocent people exhibit the same characteristics that you take as evidence of Leela cheating". If your case was simply "not-much-red => cheated with Leela" then this Euro pro game would be a counterexample so damage it (to support it you'd need to analyse lots of random games of others (what my recent post starts to do and I believe you've done some too) and show they all had lots of red). However, as you are only using "not-much-red" as the first stage, and then doing a more detailed tenuki/sequence analysis, showing another game which looks guilty on the not-much-red aspect but not with the tenuki analysis would strengthen the case. Of course we'd then need to check how valid is this tenuki analysis, with only a few data points it's going to be hard to prove much, but maybe it could work like that chess example. And avoid cherry picking.


He did note this in the pdf (post link for convenience) and used 0.10 for that game.


When I did the Leela top 3 analysis a while ago I used 50k nodes per move (which takes about 45 seconds on my 5 year-old-and-no-GPU laptop) because that's what the initial investigation into Carlo's game used. I wonder where it came from, plucked out of the air/arse? It would have been a good idea to find out the specs of Carlo's computer (let's assume he didn't use a remote one) and with reference to move times in the game so the node count was plausible for cheating in that game. Or failing that survey some people and find a typical value. But the concern about too low playouts is real, particularly as Leela 0.11 starts off liking moves favoured by the policy network which is an excellent model of "What is the human good shape intuition move in this position?" and tends to switch to "Leela but not human" style moves only after more analysis.


Isn't that easy to dismiss because AQ is stronger than Leela 0.11? Though it does at least show that the position is not hopeless for white after 139 and a stronger player can still win vs a weaker. What would be more interesting is if AQ as white beat AQ as black.

Uberdude already answered (thx for reading carefully)


I analyzed on older machine, so it took some time.


We spoke on definition of tenuki here, and I agree it is very subjective.
For this research, I considered it a move that is away from current stream of moves, or particular group, and most importantly - which is not forced.
In a move which is not forced we can more clearly see strength of player.


Yes, it would be good to analyze some games in other AIs, but I am with very limited time and resources.

Since I made histograms of all games from this year A league, I did consider it, but dropped it.
Main focus is question: what is the difference of suspects game on internet, and in live games?
Because that is the difference we are researching. If someone else plays to similar to program - examine him.
I wrote that only handful of games had diagrams with very little red. And none of those games is so similar to Leela like Metta's two games.


"Not much red" approach is similar to statistics used (it used same data, after all). It is just case for suspicion.
Most important part is comparison of every move. I will try to explain it more in updated paper.


Please note that I examined every move, and that I conside tenuki moves as more important. They are in no way forced.
On the other side, forced moves are considered of less importance.
This is attempt to try to find moves which are more important - something that first analysis lacked.

Here is another flaw. What if we are analyzing a move that Leela suggests as good, but only after let's say 50 nodes (= 40 / 60secs without a dedicated GPU = 15secs with a standard GPU), but the accused player took only 5/10 seconds to play it?
In all analysis we've discussed so far has anyone considered every move for the same time that the accused players actually used?

Otherwise all these analysis are almost nil

This is a valid point, I don't know how many games from IGS were saved with move timestamps. On KGS I think these are there by default, but IGS...

_________________
North Lecale

Without also specifying computer power time spent on move cannot be matched with number of nodes (just proportional with unknown constant), hence

If that information is not available (I think it would be reasonable for the referees to have required he provide it) then you could guess some typical laptop/desktop spec. As Carlo is doing a PhD on deep learning the assumption he doesn't have access to a remote monster computer may be false. On the other hand he did play fairly fast, and ignoring how strong the bot would be at high speed I think it would be physically difficult to use a bot at a sustained pace of e.g. 15 seconds a move, of course using a bot to find a sequence and then playing it out quickly if it goes as expected from previous analysis would be possible. But iirc Aja Huang did play as Master/Magister at 20 (or was it 30? I know Nie Weiping was 60) seconds a move, with AlphaGo I heard only using about 7 seconds a move (thanks TPUs!) to give him time to move the mouse, input moves etc...

If I am not mistaken, in PGETC sgf files there is a time stamp?

This could be number in brackets, in the end, indicating remaining time:
;B[pg]BL[1864]
;W[nj]WL[938]
;B[pk]BL[1845]
;W[pj]WL[929]
;B[qk]BL[1836]
;W[rk]WL[926]
From Metta-Ben David game
http://pandanet-igs.com/system/sgfs/637 ... 1511906173

Move 139 is on Q9, which, if I guessed correctly is B[pk], for which 21 seconds was spent.
Checking would be nice to be done here.

Hello Maf,

here is analysis.
It consists of same data as in first analysis and following documents.


I tried to resolve some uncertainties regarding methodology which were spotted and discussed here.
Chart with move difference is added inside, in previous version it was in following xls document.
I made some small corrections in text, in order to make it more clear.
I have mentioned other games and preliminary research, which is important to show how I got to two analyzed games.


You can see easily that is the case in both versions of this analysis.

You are, indeed, correct:
- https://www.red-bean.com/sgf/properties.html#BL
- https://www.red-bean.com/sgf/properties.html#WL

@Charlie : There's a difference between a "public duty" as a referee and a normal player.

If you're accused of cheating and the situation raise a big controversy, you're not in position to be a referee. Because then your decisions are weakened in the eyes of the whole go community. Or, in other words, the situation you're in will affect negatively your job as a referee.

I completely agree. I was being facetious.

As soon as the original accusation was upheld by the referees, the damage was already done and, as I wrote very early on in this rather long thread, there ceased to be a "right" way for either Carlo or the referees or other players to act. Avoiding such situations in the future should now be our only goal.

Unfortunately, we need to extract a screw and have only a hammer. Until someone invents a screwdriver, we have to accept that removing the screw is impossible.

EDIT: Chess players have screwdrivers but they've had the advantage of decades of research. As it is, the pace of development in the Go world is smashing any records that they have set in the past.

Precisely. Until further notice there should be no cash prizes and no ranking awarded in online tournaments. The results of games played online should receive the merit that they deserve. No merit.

I appreciate a lot the analysis Milos Bojanic performed as it provides more insights on some points. In particular, looking at the selected important moves is a good idea. However, I am not sure if the tenuki moves are well defined. The stronger the players are they are better at deciding when to tenuki and when not. Some moves may look forced for us but a much stronger player could tenuki them with ease. Are the ladder breaker moves tenuki. What about a move in an opposite corner that prevents a setting of a ladder that is hard to spot in just one specific variation of a sequence played elsewhere. I guess we have to wait for stronger bots available to the public that would help us to establish what moves to pick as the important ones to judge how strong the player is or if he/she cheated by using AI.

On the computer Carlo Metta might have used in his PGETC games. In the Italian appeal they specify what computer they performed their counter-analysis on: Intel Core i7, 2.60 GHZ, RAM 16GB, GPU NVIDIA GeForce GTX 960M. Operating system - Windows 10. They also say there that it analyses about 100k nodes in about 30s. I asked the question what computer Carlo used in his PGETC games and the answer I got (from Mirco Fanti, the Italian team captain, as he insisted any questions should not be asked Carlo directly but should go through him) that it was the one used in the analysis. I conclude from this that most (in not all) of the Italian counter-analysis was done by Carlo himself. This is fine, though it raises the question why the Shakhov-Metta game provided "presumably by mistake" was not excluded from the analysis, why the mistake was not discovered at that point.

The discussion here is mostly about analyses and how difficult it is to do them properly and to get reliable results from them. For me, the most relevant evidence remains the Shakhov-Metta game. The Italian explanation raises only more questions (besides the one mentioned above):
- if someone wants to show his game at a go club, would he use his laptop or present the game on a real go board; I find the later more likely, though do not refute the first option
- if someone shows his game to a public/friends on his laptop I guess there would be questions asked (why not this move, should you or your opponent not play another sequence) and there would be variations in the game record; there are none in the one provided by Carlo
- and finally and most importantly (and already mentioned in this lengthy topic), why would anyone show the game with a board turned by 180 degrees (from white's point of view when the player saw it from black's point of view while playing the game on KGS)

And a little bit from the analysis I presented that I do not remember discussed here. I can very well understand that Carlo had a bad tournament at WAGC and underperformed there for whatever reasons. What I do not understand (if he did not cheat on internet) is that in his regular games (including WAGC) he finds moves better than Leela's top choice more often (almost 3 times) than in his PGETC games where he presumably used AI, so he was not trying hard to find the best moves. Sure, the number of such moves is quite small, so the effect may disappear when more games would be considered, but I still find this interesting.

I don't know about the only, but certainly it should be our goal.

We can learn from them. But much remains to be done. A big step will be to get away from the fixation on matching plays with choices of bots, which is weak evidence. Chess players are able to rate the difficulty of individual plays, which enables them to eliminate easy plays from consideration. Currently we have to rely upon humans to do that, despite differences in judgement between players. Bojanic does a service by identifying forcing plays and tenuki. One foot in front of the other.

_________________
The Adkins Principle:

At some point, doesn't thinking have to go on?

— Winona Adkins

It is not desirable to wait for stronger bots or for bots which have been developed to evaluate the difficulty of plays in order to have them sort important plays from unimportant plays. A practical approach is to have a panel of strong players to do that, if need be. You can let them work independently, and then identify plays upon which they agree, or let them consult with each other and come up with some choices.

In addition, much research needs to be done in detecting cheating at go. We do not necessarily need to follow the exact path taken in chess. lightvector's work developing neural nets to model players of different strengths (see viewtopic.php?t=15757 ) might be a place to start with rating the difficulty of plays, for instance. Another thing that might be done is to create a database of games where one player is known to have cheated. (Because he or she did so by request, in order to add a game to the database.) You probably would want to have a database in which the same players did not cheat, for comparison purposes.

_________________
The Adkins Principle:

At some point, doesn't thinking have to go on?

— Winona Adkins

Thank you. I'm sorry that I repeat myself, but I'm still looking for many games by other players checked in the same way, to see if they exhibited that same pattern as the games by CM. Earlier, I gave some naive ideas why that's a possibility. The next step would be to see just how outstanding this truly is. Unless we're sure he's an exception, the whole approach is, as far as I can tell, just not reliable. If that's not currently possible for you, that is fine, it should just be noted.

After move 139 the black advantage Leela 0.11 estimates is 70%, but AQ finds it only 55%. It is white's last chance to overturn the game, and AQ indeed can win this position with white against Leela 0.11. That means AQ's evaluation of this position is probably more accurate. AQ vs AQ is not interesting at all in this discussion. It is about a different evaluation. AQ also thinks that white 70 was a big mistake (cutting off two stones is too small).

Calling 59 and 65 in game 2 "tenuki" moves is beyond me. They are almost forced answers. Especially 65 is an "only" move. Then 87 is again not a tenuki but a direct answer to 86 into a double sente area. After that white plays slack and black wins about 10 points in that area. In sente. 97 is not a tenuki, black had sente and the area in the lowerright was finished for the time being.

Then some here (correctly) pointed to the time record in the SGF. I already did the analysis. This record shows that black in this game played a lot faster than white, whcih might make one suspicicious, BUT a lot of moves were made so fast that there was simply not enough time to transfer the white move to Leela 0.11 and wait for a reasonable analysis from that engine. 80% of the black moves were fast moves.

Maf,
it is written in paper and explained earlier, here it is again:
in preliminary analysis I examined all 180 games from A league, with quick GRP settings.
Less than 10 games were suspiciously similar to Leela, and few after quick analysis showed differences and were discarded (one Metta's, btw).
Only few games had very similar moves to Leela's - and two of them were Metta's. It is very clear why he stands out most.
Also I consider his games easiest for analysis, because they are most similar to Leela's.

BTW I started analysis because of other player. His game is very similar to Leela, but some of the moves are different, and he is stronger. Overall, it is more difficult case.