drogo wrote on 09/23/10 at 14:50:41:


Finally, somebody from chess.com acknowledges that statistical testing may be useful, and they haven't done it yet!

Also, this comment that "no human passed the 65/75/85 threshold" is not true. You have had numerous examples of humans passing that threshhold, just not for more than 20 games. When you consider that fatigue is a major cause of human error and that CC chess removes that factor, isn't that threshhold a bit tenuous given all the factors that others here have pointed out?

Also, consider that in the recent WC match between Anand and Topalov, top players are surprised by Anand's errors. They expected a much lower rate of mistakes!

Zygalski wrote on 09/23/10 at 13:34:43:

Thanks for the reply, it makes sense. I don't mean to be rude, but if I'm correct, you're not of IM or GM stength at correspondance chess: in which case, I don't see how it is possible for you to judge such a case. Of course, you're not responsible (in fact, yes, you could be better at correspondance chess  ), but the choice of expert from chess.com is open for discussion...

@ Drogo: I find it strange to state that "It is not possible to calculate the probability of error because there is simply no data". I'm no expert in statistics but if data from correspondance chess from the pre-computer area are used to calculate an avarage for t1, t2, t3 (of 60%, 75% and 85%, respectively according to Zygalski's post), they could be used to calculate a standard deviation and a confidence interval. Thanks to these values, you can say that player YD is a cheater according to his/her last 20 games with a risk of X% of being wrong. Of course, whether the set of data is relevant or not (both the original data and the games from YD) is another issue, as raised by TN and others. But at least, the t3/t4 test would have some statistical signification: if you're unable to associate a risk or error with a decision, you're not doing statistics!

Zygalski wrote on 09/23/10 at 10:46:47:



I've read somewhere that when chess started getting serious in the mid/late 1800s, players would shake hands before the game as confirmation that they would accept no outside assistance. 

Today, it seems hard to avoid accusations of cheating even in an otb world championship match. 

Having a special "police force" with secret formulas to determine and publicly shame statistically found suspects sounds like overkill for a game that's supposed to be played for fun. 

My best suggestion would be to go back to the "handshake", i.e. let them before the start of a game click to approve an agreement of not to cheat and not to accuse, on their soul or honour - and leave it at that. As I understand it there are no starting fees or money prizes in these chessdotcom tms - so why make such a big deal of it?


Otherwise, there are two choices: either allow everything, which removes both cheating and accusations of cheating or use a statistical system that may catch the most stupid cheaters and potentially some innocents - but it will never stop accusations of cheating, which is just as cancerous a problem as actual cheating...

T3 or T4 - there are a limited number of moves to choose from at every turn, and the stronger the player the fewer moves get consideration. With small differences in engine evals it's hard to say more than: X chooses moves similar to rybka at 18ply, which doesn't mean that X is using rybka. Engines are programmed to play more humanly, so maybe rybka is playing like X?

Anyway, people could always use an engine for a quick blunder check - or would you stipulate that everyone must make very suboptimal moves regularly? 

Players intent on cheating (or afraid of being suspected) could perhaps check rybka's top 3-4 and make sure to choose a fifth one, though there's no guarantee that the fifth move won't be number 1-3 on the next ply depth.


To sum up, chess.com can ban their players all they like but I think we all agree they should stop publishing names of individuals as "known cheaters" on the internet.

Well, this is my final entry on the subject. Good luck.

TN wrote on 09/23/10 at 07:28:52:


a) How can you know that?
b) Nothing can be proven: either that he cheated or that she didn't cheat. I guess Yelena doesn't have multiple webcams in her house to broadcast all her actions, 24 hours per day.
c) The comparison was between supposedly current UNASSISTED CC games and pre-1980 CC games or modern OTB games.
d) Chess.com has a bunch of titled players. The highest rated GM is Julio Becerra, rated at least 300 points below Yelena on chess.com. Other GM's play there and their ratings are even smaller.

You mean there's something wrong with throwing people in the well and see if they float?

Zygalski wrote on 09/23/10 at 07:32:55:


Comparing Dembo's play to correspondence games from the 2000s instead of the 1960s or 1970s would be an improvement. 

As chess players have become steadily stronger over the years, it shouldn't come as a surprise that the top correspondence players on chess.com are playing better chess than the top correspondence players of the 1960s. The influence of the engine has meant that humans today have much more effective 'computer eyes' than the old masters.

lol where's a non-cheating GM around to prove your moves are human when you need him? I'm not going to bother to attempt a serious response to something so inane. The chess world does not revolve around chess.com.

It's like a broken record with these guys. They repeat the same things even after glaring flaws in their logic have been pointed out (more than once). Good luck with your mission (which appears to have the inevitable result of discrediting yourself).

The irony of all this (at least from my perspective) is that I consider this use of computer engines to be perhaps one of the most abusive. Objections to abuse of statistics to make defaming claims are not trivial. You have been warned.