4NCL Online
 JustinHorton
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Re: 4NCL Online
Yes, I'm talking in the scientific sense, can someone else run precisely what he runs.
"Do you play chess?"
"Yes, but I prefer a game with a better chance of cheating."
lostontime.blogspot.com
"Yes, but I prefer a game with a better chance of cheating."
lostontime.blogspot.com

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 Joined: Thu Jun 06, 2019 4:18 pm
Re: 4NCL Online
Thanks Matt. Once you said it, it made perfect sense  selecting computer moves at the same rate as a 2300 can have large statistical significance, even if the play is not remotely at the level of a 2300 (and wouldn't be if a 1500 was picking computer moves for some fraction of moves and for the rest playing whatever their first choice was).Matthew Turner wrote: ↑Mon Jun 15, 2020 4:03 pmJoe,
It is important to note that we are talking about matching a computer's moves at the same rate as a 2300 as distinct from playing at 2300. So Magnus Carlsen is better than me, not only because he plays more computer moves, but also because he is better than me at knowing when it is important to play a computer move.
So, it is perfectly conceivable that a 1500 could 'perform' at 2300 by selecting the computer move half the time rather than all the time. In reality though, I am not sure that this would persist for very long, they would either get bored and stop or be drawn into playing more computer moves.
This point also shows the deficiency of many arguments along the line of 'I looked at X's games and they didn't seem anything special; in fact in several he blundered and ended up losing.'  huge statistical outliers are still huge statistical outliers which require an explanation, whatever the actual result of the game.
BTW I found your earlier point compelling  if you have any measure of 'accuracy of play', and then find this measure produces far more extreme values in online play than in OTB play (or within two subsets of online play by the same player), that is strong evidence of assistance even if in any one case one could adduce arguments to explain this away. In this respect I note that lichess stopped women's prizes in its Titled Arenas, because it said they had detected too much account sharing.
Regarding levels of significance generally: in particle physics one reason 5sigma is used is because even if you have lucky fluctuations, underestimate your errors etc, then you would have still have at least 34 sigma of significance. This is a similar idea to what someone [edit: actually you] mentioned earlier in the thread, namely take whatever significance you would like to have for a ban, and then add one sigma to it (to account for good days, freshness vs tiredness etc etc).
That said, there are still 5 sigmas and 5 sigmas (there is at least one dark matter experiment that claims > 10 sigma significance and noone else believes them). Two mutually supporting 3.5 sigmas from different directions (which combine to 5 sigma) is perhaps much better than a single 5 sigma from one indicator.
Regarding the scientific method, peer review etc: this scientist would, perhaps cynically, regard it as having some analogue to sausage making: if you like the product, don't look too closely at what goes into it.
 JustinHorton
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Re: 4NCL Online
Any chance of anybody explaining sigma to the nonscientists
"Do you play chess?"
"Yes, but I prefer a game with a better chance of cheating."
lostontime.blogspot.com
"Yes, but I prefer a game with a better chance of cheating."
lostontime.blogspot.com
 IM Jack Rudd
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 Location: Bideford
Re: 4NCL Online
Sigma is the standard deviation of a distribution. If the distribution is Normal, roughly twothirds of all results will fall within one sigma of the mean, and nineteentwentieths of all results will fall within two sigmas of it.
 JustinHorton
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Re: 4NCL Online
That may possibly shift the locus of incomprehension rather than remove it
"Do you play chess?"
"Yes, but I prefer a game with a better chance of cheating."
lostontime.blogspot.com
"Yes, but I prefer a game with a better chance of cheating."
lostontime.blogspot.com

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 Location: Awbridge, Hampshire
Re: 4NCL Online
as in this graph:IM Jack Rudd wrote: ↑Tue Jun 16, 2020 5:43 pmSigma is the standard deviation of a distribution. If the distribution is Normal, roughly twothirds of all results will fall within one sigma of the mean, and nineteentwentieths of all results will fall within two sigmas of it.

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Re: 4NCL Online
Don’t know if I’m going to help or not but I’ll give it a go.JustinHorton wrote: ↑Tue Jun 16, 2020 4:56 pmAny chance of anybody explaining sigma to the nonscientists
As Jack mentioned, sigma refers to the standard deviation  this is basically just a measure of how much a given quantity varies from the average.
Taking male height as an example  the average is about 5’10” with standard deviation (sigma) of about 4 inches. So someone with a 1 sigma variation from the average would be 6’2”, quite tall but not particularly remarkable. A 4 sigma variation would be 16 inches above the average, or 7’2”  very much an extreme outlier.
 JustinHorton
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Re: 4NCL Online
Thanks all
"Do you play chess?"
"Yes, but I prefer a game with a better chance of cheating."
lostontime.blogspot.com
"Yes, but I prefer a game with a better chance of cheating."
lostontime.blogspot.com

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Re: 4NCL Online
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Last edited by NickFaulks on Tue Jun 16, 2020 7:17 pm, edited 1 time in total.
If you want a picture of the future, imagine a boot stamping on a human face — forever.

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Re: 4NCL Online
The graph above is the real deal; saying something is 2 sigma, or 3 sigma, or 4 sigma, is a measure of how often something is likely to happen.
Let me put another (identical, but differently phrased) scale to this:
Suppose chess player Knightie McKnightFace plays six tournaments a year and has a stable rating. Then
1 sigma outperformance = happens 1 time in 6, the best tournament performance they play that year
2 sigma outperformance = happens 1 time in 50, a onceinadecade performance, one of the few best tournaments of their life
3 sigma outperformance = happens 1 time in a 1000, the sort of performance a very active player going to tournaments every other weekend delivers once in their entire life
4 sigma outperformance = happens 1 time in 30,000, the best tournament performance that an active player has ever been present at  something roughly comparable to winning a 10player allplayall against equal opposition with 9/9.
5 sigma outperformance = happens 1 time in 3,000,000  take all the GMs in the world there have ever been, take every tournament they have ever played in, from when they were U7 to when they died, and you expect that not one of these performances reach this standard  on a very rough estimate, this is something like a player ~190  200 (say you or me) playing in the main British championship and starting off with 6/6 or 7/7.
In a physics context, stuff under 3 sigma often goes away  in chess an active arbiter might see several 3 sigma performances a year. Once you get to 4 sigma (is this the same as Regan z=4?) or 5 sigma (or more) you are really in the 'what is going on?' category.
Let me put another (identical, but differently phrased) scale to this:
Suppose chess player Knightie McKnightFace plays six tournaments a year and has a stable rating. Then
1 sigma outperformance = happens 1 time in 6, the best tournament performance they play that year
2 sigma outperformance = happens 1 time in 50, a onceinadecade performance, one of the few best tournaments of their life
3 sigma outperformance = happens 1 time in a 1000, the sort of performance a very active player going to tournaments every other weekend delivers once in their entire life
4 sigma outperformance = happens 1 time in 30,000, the best tournament performance that an active player has ever been present at  something roughly comparable to winning a 10player allplayall against equal opposition with 9/9.
5 sigma outperformance = happens 1 time in 3,000,000  take all the GMs in the world there have ever been, take every tournament they have ever played in, from when they were U7 to when they died, and you expect that not one of these performances reach this standard  on a very rough estimate, this is something like a player ~190  200 (say you or me) playing in the main British championship and starting off with 6/6 or 7/7.
In a physics context, stuff under 3 sigma often goes away  in chess an active arbiter might see several 3 sigma performances a year. Once you get to 4 sigma (is this the same as Regan z=4?) or 5 sigma (or more) you are really in the 'what is going on?' category.

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Re: 4NCL Online
So anyway, just to clarify re: Regan tool. If you are still within known theory you can cheat to your heart’s content?!

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Re: 4NCL Online
My next online handleJoseph Conlon wrote: ↑Tue Jun 16, 2020 6:53 pmSuppose chess player Knightie McKnightFace plays six tournaments a year

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Re: 4NCL Online
Yes, so long as the tool knows that you're in known theory..... Which must be a genuinely very difficult task these days.Richard Bates wrote: ↑Tue Jun 16, 2020 7:19 pmSo anyway, just to clarify re: Regan tool. If you are still within known theory you can cheat to your heart’s content?!
My a priori assumption was definitely that there'd be relatively much more cheating by looking up opening notes etc in the 4NCL online than by copying engine moves.

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Re: 4NCL Online
My take on it (based on A. Elo's original systen) 
In the Elo system the interval of a category is defined as one Standard Deviation (1 sigma) [corresponding to a band 200 Elo points wide with 2000 "as a reference point" both "already steeped in tradition" when Elo chose to use them. JM]
Rating categories (based on a 200 point interval and with 2000 as midpoint) 
3000+ Artificial Intelligences
2800+ Human World Champion & contenders
2600+ Strong GMs
2400+ IMs & weaker GMs
2200+ FMs & National Masters
2000+ Candidate Masters & other experts
1800+ Category 1 amateurs
1600+ Category 2 amateurs
1400+ Category 3 amateurs
1200+ Category 4 amateurs
1000+ Novices
Each step up/down from the 2000 midpoint is 200 points and thus 1 sigma (one Standard Deviation).
For a player rated exactly 2000 a 
2200+ performance is 1+ sigma
2400+ performance is 2+ sigma
2600+ performance is 3+ sigma
2800+ performance is 4+ sigma
3000+ performance is 5+ sigma
3200+ performance is 6+ sigma
And so on...
The theory underpinning it is given by A. Elo 
A player will perform around some average level... Deviations occur... (with) large deviations less frequently than small ones. These facts suggest the basic assumption of the Elo system 
The many performances of an individual will be normally distributed... [as shown by the wellknown symmetrical bell curve, as given further above in this thread. JM]
"Extensive investigation (Elo 1965, McClintock 1977) bore out the validity of this assumption. Alternative assumptions are discussed..." [elsewhere  JM]
"Statistical and probability theory provides a widely used measure of these performance spreads [deviations from the average  JM] a measure which has worked quite well for many other natural phenomena... Standard Deviation." [1 SD is denoted by 1 sigma  JM]
"The central bulk [of the bell curve]  about twothirds [68% JM]  of an individual's performances lie within 2 Standard Deviations" [i.e. minus 1 to plus 1 SD (1 sigma to +1 sigma. And that leaves 32% of the player's performances outside of that central bulk. With 16% higher than +1 sigma and the remaining 16% being lower than 1 sigma].
Q.E.D. (At least I'd like to think so.)
In the Elo system the interval of a category is defined as one Standard Deviation (1 sigma) [corresponding to a band 200 Elo points wide with 2000 "as a reference point" both "already steeped in tradition" when Elo chose to use them. JM]
Rating categories (based on a 200 point interval and with 2000 as midpoint) 
3000+ Artificial Intelligences
2800+ Human World Champion & contenders
2600+ Strong GMs
2400+ IMs & weaker GMs
2200+ FMs & National Masters
2000+ Candidate Masters & other experts
1800+ Category 1 amateurs
1600+ Category 2 amateurs
1400+ Category 3 amateurs
1200+ Category 4 amateurs
1000+ Novices
Each step up/down from the 2000 midpoint is 200 points and thus 1 sigma (one Standard Deviation).
For a player rated exactly 2000 a 
2200+ performance is 1+ sigma
2400+ performance is 2+ sigma
2600+ performance is 3+ sigma
2800+ performance is 4+ sigma
3000+ performance is 5+ sigma
3200+ performance is 6+ sigma
And so on...
The theory underpinning it is given by A. Elo 
A player will perform around some average level... Deviations occur... (with) large deviations less frequently than small ones. These facts suggest the basic assumption of the Elo system 
The many performances of an individual will be normally distributed... [as shown by the wellknown symmetrical bell curve, as given further above in this thread. JM]
"Extensive investigation (Elo 1965, McClintock 1977) bore out the validity of this assumption. Alternative assumptions are discussed..." [elsewhere  JM]
"Statistical and probability theory provides a widely used measure of these performance spreads [deviations from the average  JM] a measure which has worked quite well for many other natural phenomena... Standard Deviation." [1 SD is denoted by 1 sigma  JM]
"The central bulk [of the bell curve]  about twothirds [68% JM]  of an individual's performances lie within 2 Standard Deviations" [i.e. minus 1 to plus 1 SD (1 sigma to +1 sigma. And that leaves 32% of the player's performances outside of that central bulk. With 16% higher than +1 sigma and the remaining 16% being lower than 1 sigma].
Q.E.D. (At least I'd like to think so.)
To find a for(u)m that accommodates the mess, that is the task of the artist now. (Samuel Beckett)
 IM Jack Rudd
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Re: 4NCL Online
Be careful with this analysis: fiveround tournaments and nineround tournaments will probably show significantly different numbers when it comes to variation around a TPR.