+- Forums (https://www.chessscotland.com/forum)
+-- Forum: Members Only (https://www.chessscotland.com/forum/forum-16.html)
+--- Forum: International Tournaments (https://www.chessscotland.com/forum/forum-8.html)
+--- Thread: Bulgaria - Summer of Chess (/thread-496.html)
Re: Bulgaria - Summer of Chess - Andrew McHarg - 31-05-2013
Phil Thomas Wrote:One thing I'm not sure about perhaps you can help?
In the lottery analogy if there are 14,000,000 possible combinations and 140,000,000 lucky dips were sold then typically one would expect around 10 winners.
For DNA tests are all possible combinations equally well populated? This does seem to be a hidden assumption in the stats.
Well, normally during something like a paternity test they might analyse a matter of hundreds of DNA nucleotides, which will almost always be enough to ascertain which one of only a few men are the father. However, it's quite possible that a few other people on the planet have a section of DNA which is the same as this particular person. But if we look at every single nucleotide within a person's DNA then I'm convinced that everyone is totally unique. I mean, even identical twins (such as me and my brother) will not actually have an identical DNA sequence as adults. The reason for this is that mutations spontaneously occur within DNA, often dictated by environmental factors (such as exposure to UV). It's very likely that some of my brother's DNA has mutated in different ways to mine. So in that sense, every DNA combination is equally well populated, as long as your analysis was deep enough to look at the entire genotype of every individual. Currently this would cost a lot of money and take far too long; but it's very likely to be possible in the future - even if dangerously intrusive.
But if we are talking about only small sequences of DNA strands then I would say it would seem to defy natural selection if some weren't more common than others. Some variations of particularly important DNA sequences will be significantly more successful than others, and hence natural selection states that they will be more abundant. This is even still true to a large degree in an advanced civilization like humans. For instance, genetic codes within people that make them more susceptible to certain life-threatenining illnesses are likely to be rarer because the carriers of such codes will likely die sooner/more frequently than others. So if we only scratch the surface then I'd agree that DNA combinations are not equally weighted.
I do think it's interesting to note the similarities between DNA evidence and Chess engine match-up though, as I think it gives a real life example of where statistics are used in court to convict people. If the odds in Ivanov's case are similarly compelling then I see no logical reason why they wouldn't also be treated as conclusively as DNA evidence is, and hence prove Ivanov's guilt beyond any reasonable doubt.
Re: Bulgaria - Summer of Chess - Phil Thomas - 31-05-2013
Andrew,
After playing around with various key words Google came up what is essentially a peer reviewed document on forensic DNA testing
<!-- m --><a class="postlink" href="http://ota.fas.org/reports/9021.pdf">http://ota.fas.org/reports/9021.pdf</a><!-- m -->
OTA = Office of Technology Assessment.
An american outfit, presumably government sponsored.
Rather a long document: most pertinent pages for the DNA forensics question I raised are 67 and 68.
Basically conclusion is rather surprisingly that the question has not been answered yet.
Key quote from page 67 is " these basic calculations are only valid when applied to populations in which the DNA fragments are statistically independent"
Actually I do suspect that Ivanov is guilty but if this goes to court his lawyer could claim that his client used Houdini to train himself and for that reason (more frequently than for other players of his standard) his moves tend to match those of Houdini.
And furthermore you stated that Magnus Carlson produces fewer match ups with Houdini. I put it to you the jury that that Carlson does not use Houdini in the same manner as my client. Therefore I put it to you that the comparison with the world champion is not valid .... Answer Yes or No to the Court.
The obvious action required here is of course to to ban live broadcasts of games and feed in a delay of 10 minutes or more.
The analogy between lottery stats chess moves stats is an interesting one.
Genetics defines my family.
Chessmoves are my friends.
As the saying goes you can choose your friends but not your family. =)
Re: Bulgaria - Summer of Chess - WBuchanan - 31-05-2013
It seems the comparison with DNA use in court throws up valuable lessons. It’s very easy to blur the distinction between “the odds” and the claims made for those odds - as they are two different entities.
Anyone speaking of odds of billions to one is very likely to be overlooking one or two practical realities along the way. Contrary to those claims that the number is too big to doubt, it seems DNA matching is quite a complex, subjective process with lots of choices made before that impressive, ‘unchallengeable’ statistic is unveiled by the guy in the white gloves to wow the court.
First let’s examine the goods from a commonsense viewpoint. If the odds against a DNA match being wrong are, as claimed, billions to one, then in a population of 7 billion - the vast majority of whom have never been convicted on DNA evidence - you would be unlucky if there were even ONE conviction based on DNA evidence where the DNA evidence was later found to be wrong. However a quick search turned up half a dozen (I won’t post links as they are to crimes). There seem to be plenty more. The main problem being contamination en route to the lab or before. In others it was (to be charitable) over zealousness on the part of officials talking up weak evidence.
This study puts the theoretical claims into perspective:
False result fear over DNA tests
Nick Paton Walsh
The Observer, Sunday 27 January 2002
“One in every hundred forensic tests performed on the DNA of suspected criminals may give a false result, according to the first research of its kind into laboratory error rates.”
…The findings will shock British DNA laboratories, which deny that errors exist.
…British forensic experts expressed alarm at the errors and stressed they were more numerous than expected.”
<!-- m --><a class="postlink" href="http://www.guardian.co.uk/uk/2002/jan/27/ukcrime.research">http://www.guardian.co.uk/uk/2002/jan/2 ... e.research</a><!-- m -->
DNA can be planted; although perhaps not very likely, the possibility means those billion to one odds go out the window. It also transpires that DNA can be easily fabricated in the lab.
Useful lawyery essay here featuring the issues <!-- m --><a class="postlink" href="http://www.lawlink.nsw.gov.au/lawlink/pdo/ll_pdo.nsf/vwPrint1/PDO_dnadealingwithincourt">http://www.lawlink.nsw.gov.au/lawlink/p ... ithincourt</a><!-- m -->
As Phil notes, the assumption of statistical independence (needed because they multiply the probabilities for each DNA fragment together, which leads to the quoted small probability of a mismatch) is not guaranteed, and has meant that for example in some populations a much higher rate of pairs of people matching than would be predicted by the ‘statistics’ in use. See para 28 here, where 122 pairs of profiles matched in the Arizona offender database of 65,493 profiles. <!-- m --><a class="postlink" href="http://www.state.il.us/court/opinions/appellatecourt/2012/2nddistrict/2091328.pdf">http://www.state.il.us/court/opinions/a ... 091328.pdf</a><!-- m -->. Also 206 matching pairs were found from 33,858 profiles in a survey of DNA databases by the National Institute of Forensic Science, <!-- m --><a class="postlink" href="http://www.lawlink.nsw.gov.au/lawlink/pdo/ll_pdo.nsf/vwPrint1/PDO_dnadealingwithincourt">http://www.lawlink.nsw.gov.au/lawlink/p ... ithincourt</a><!-- m -->
So, no billion to one chance there. These are partly due to using partial DNA matches rather than full ones – that’s what you get when you widen the goalposts, as people do.
DNA testing IS useful, just as probability calculations for chess engine matches IS useful. It’s not the science that’s at fault, but the human (over) interpretation. Blind faith in numbers isn't standing up.
Re: Bulgaria - Summer of Chess - Phil Thomas - 01-06-2013
Walter,
what you have published is very close to the conclusions I reached from the link I posted. Looks like the CS notice board is moving into the tried and tested peer group review methodology.
For me any lab results quoting odds of billions to one for anything has to be questionable. Consider the chances of human error in labelling samples incorrectly, or the well known but not controlable issues of degradation or contamination of sample collected from crime scene, potential cross contamination from suspect DNA sample handled in same lab, let me add two more -unfortunate typos on a querty keyboard where the reader reads the right result but characters are not perfect, identical twins that have not met for decades. Hidden in that long report I linked to is the comment that ideally suspect and crime scene DNA should not be handled in the same room.
I want to maintain brevity in this posting but traditional police methodology still has a key role. From page 68 " although any reported identification frequency represents an estimate to be used in conjunction with other evidence linking a defendent to a crime".
While this appears to take the thread off topic I still maintain that Boris Ivanov might be able to put up a successful defense in court. Based upon ..............Ivanov trained with the Houdini chess engine and tried to imitate its style. He succeeded - no other leading chess player has had the same training method. My (pseudo)client has been prejudged by journalists and discussion fora making a fair trial impossible.
The odds against errors in reports made by journalists are considerably shorter than for reports made by DNA testing labs
Harry Houdini was a master of escapology; how appropriate that his name was used for this chess engine. If frustrated by the prowess of Houdini just remember that you are better at kick boxing than the computer -
<!-- m --><a class="postlink" href="http://www.nytimes.com/learning/general/onthisday/bday/0324.html">http://www.nytimes.com/learning/general ... /0324.html</a><!-- m -->
PS who saw my deliberate typo on first read through.
Re: Bulgaria - Summer of Chess - Graham Kerr - 01-06-2013
Phil Thomas Wrote:While this appears to take the thread off topic I still maintain that Boris Ivanov might be able to put up a successful defense in court. Based upon ..............Ivanov trained with the Houdini chess engine and tried to imitate its style. He succeeded - no other leading chess player has had the same training method. My (pseudo)client has been prejudged by journalists and discussion fora making a fair trial impossible.
...but Houdini 3 had only been on the market for a matter of weeks...
BTW, i thought DNA was the National Dyslexic Association ;P
Re: Bulgaria - Summer of Chess - Phil Thomas - 01-06-2013
Graham Kerr Wrote:[/quotePhil Thomas Wrote:...but Houdini 3 had only been on the market for a matter of weeks...
At which point I shall produce an expert witness to testify on the differences between Houdini 2 and Houdini 3. That should baffle the jury and encourage a not guilty verdict.
And since you have produced no proof to the court that Boris purchased Houdini 3 then all the analysis will have to be done again on Houdini 2 this time witnessed by both parties. In the interest of fairness all the clearly forced recaptures must be eliminated from the stats.
Re: Bulgaria - Summer of Chess - Graham Kerr - 06-06-2013
<!-- m --><a class="postlink" href="http://www.chessbase.com/Home/TabId/211/PostId/4009997/the-show-goes-on-ivanov-in-kustendil-030613.aspx">http://www.chessbase.com/Home/TabId/211 ... 30613.aspx</a><!-- m -->
A good read!
Re: Bulgaria - Summer of Chess - Phil Thomas - 06-06-2013
Valuable posting Graham,
very interesting reading.
As always chess organisations have to be aware of the dangers of trial by journalism or trial by reputation not involving interviews with all the individuals directly concerned. Here in this article we have some high quality journalism I quote
"we recommend to Borislav Ivanov to provide his permission for conducting extensive tests on him through various technical equipment, which will be both in his favor for the purposes of clearing his name and in favor of the Bulgarian Chess Federation, which will do everything possible in the future to resolve the problem on a national and international level in case it is proven with scientific means that Ivanov does not use any unfair means during his games".
This for me is the current status in a short, succinct, fair, and balanced nutshell.
And inevitably some low quality journalism crept in. I quote from elsewhere in the article.
"But strip searches that could discover tiny receivers would require a warrant by a judge"
I am not an expert in Bulgarian law but I would have thought that permission from Boris Ivanov would have been sufficient and I doubt that a judge would have the authority to give permission - In Boris's defense when he was requested to remove clothing for a search he complied.
Re: Bulgaria - Summer of Chess - Andrew McHarg - 06-06-2013
Imagine a hypothetical situation where you are in the last round of a tournament, and anything but a loss will guarantee you winning the tournament and collecting a prize of £5000. A player graded 300 elo below you sits in front of you and emphatically demolishes you, claiming the £5000 prize. This, after already having done the same to lots of other players much stronger than he. Later analysis of the games suggests a very strong matchup with a top Chess engine.
I'd be surprised if your opinions would be so diplomatic if you were put in such a situation Phil and Walter. It's very possible that he's a genius who has just come out of nowhere. But it's far more likely he is cheating, and it just cost you £5000. You'd be very pissed off, and rightfully so.
And if this situation isn't resolved then I believe it could send Chess down a similar road to cycling. Players will find more ingenius methods of receiving computer help in order to win money and titles, knowing that the Chess community will do nothing without actually witnessing the cheating first hand. And you'll have the same doubts as you do in cycling: "...player x won that tournament", "...yea but he was probably cheating". The whole game becomes sadly pointless, and OTB becomes as ruined by cheating as online Chess largely is.
Re: Bulgaria - Summer of Chess - Phil Thomas - 06-06-2013
In that hypothetical situation I would be hacked off. Please moderate your language on the notice board.
However I still maintain that the Bulgarian chess authorities have called this one correctly. A short term suspension while they investigate with the accused (apparently) allowed to take part in the process and a process that admits the possibility of proving him innocent. And I would hope the principal innocent until proved guilty would apply
The investigation must go through a legal or quasi legal process.
"we recommend to Boris Ivanov to provide his permission for conducting extensive tests on him through various technical equipment, which will be both in his favor for the purposes of clearing his name and in favor of the Bulgarian Chess Federation, which will do everything possible in the future to resolve the problem on a national and international level in case it is proven with scientific means that Ivanov does not use any unfair means during his games".
The method happening now consists of large numbers of people who hold the same view collating their views and their evidence. This is the judicial system of the lynch mob.
I await news from Bulgaria.