[HN Gopher] A recent chess controversy
___________________________________________________________________
A recent chess controversy
Author : indigodaddy
Score : 70 points
Date : 2025-09-26 15:02 UTC (7 hours ago)
(HTM) web link (www.chicagobooth.edu)
(TXT) w3m dump (www.chicagobooth.edu)
| 5tk18 wrote:
| It is well known that Kramnik baselessly accuses everyone. The
| article seems to be more about statistics than chess, and doesn't
| make any accusations. Kind of a click bait title IMO.
| cortesoft wrote:
| It's using a random accusation as a starting point for
| explaining Bayesian analysis.
| bleuarff wrote:
| It's to be expected per
| https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...
| adw wrote:
| Which is itself intuitive if you have the prior that "making
| the claim is the stronger headline, so if the claim is true,
| it'll be in the headline"
| mrala wrote:
| The title is "Did a US Chess Champion Cheat?" and the text of
| the article uses statistical analysis to show that the person
| most likely did not cheat. What would you consider to be
| misleading between the title and the article?
| bediger4000 wrote:
| The headline also complies with Betteridge's Law of
| Headlines. It's entirely legal.
| RegnisGnaw wrote:
| This is a perfect example of https://en.wikipedia.org/wiki/Be
| tteridge%27s_law_of_headline...
| joshuat wrote:
| "Statistical analysis shows US Chess Champion most likely did
| not cheat, despite recent claims" would be nice
| thieving_magpie wrote:
| When I opened the article I thought it was going to be about
| someone cheating at the US Chess Championship.
| paxys wrote:
| Headlines following Betteridge's law were the original
| clickbait, and this definitely fits.
| 512 wrote:
| Hikaru is also notable for quickly accusing players baselessly
| rendall wrote:
| Whom did he accuse? Kramnik is _known_ to accuse other
| players. I 've never heard this about Nakamura.
| frenchtoast8 wrote:
| He's accused Luis Paulo Supi (Brazillian grandmaster) a few
| times after losing to him, and he accused Andrew Tang after
| losing to him. The latter was criticized in some online
| circles because it was seen as bullying a then 14 year old.
|
| I don't know many other notable cases of Nakamura accusing
| players of cheating. Many players dislike how Nakamura
| conducts himself on stream and how he interacts with the
| chess community and this leads to exaggeration. It's simply
| wrong to compare him to Kramnik, who has dedicated many
| hours over the last couple years to accusing players.
| wesnerm2 wrote:
| Nakamura was sued for $100 million by Hans Niemann.
|
| https://www.chess.com/news/view/hans-niemann-lawsuit-
| dismiss...
| freeopinion wrote:
| And what was the result? Weren't all counts dismissed?
| vrmiguel wrote:
| Hikaru accused Luis Paulo Supi of cheating at least twice.
|
| From his Wikipedia article:
|
| ``` In an online blitz tournament hosted by the Internet
| Chess Club in May 2015, American Grandmaster Hikaru
| Nakamura accused Supi of cheating (Supi had defeated
| Nakamura).[2] The tournament judges accepted Nakamura's
| accusation, reverted the match's result, and banned Supi
| from the tournament. Brazilian Grandmaster Rafael Leitao
| wrote in his personal website, "Accusing him of using an
| engine in this match is absurd. The match is full of
| tactical mistakes. Nakamura played extremely poorly and,
| honestly, wouldn't have survived long against any engine
| given his terrible opening.". ```
|
| Some years later Nakamura lost 4-0 and again insinuated
| that GM Supi used an engine.
|
| Despite all that, Nakamura still published a video calling
| him a "legend" for once beating Magnus in 18 moves
| giancarlostoro wrote:
| I'm just trying to figure out how you even cheat on chess, the
| only thing that comes to mind is moving pieces, and sneaking
| new ones on the board, but if there's enough cameras, how do
| you get away with it, eventually someone WILL notice, highlight
| it, point it out, and you will be shamed.
| ceejayoz wrote:
| Bluetooth buttplug (you can get such things on Amazon;
| https://en.wikipedia.org/wiki/Lovense) and an observer in the
| audience tapping out Morse code?
|
| Or, more mundanely, bathroom breaks.
| https://www.nytimes.com/2024/10/16/sports/kirill-
| shevchenko-...
|
| Your iPhone can reliably beat the best chess players in the
| world.
| AdamN wrote:
| In the old Soviet/US rivalry days there was an accusation of
| cheating that I thought was novel. The accusation was that
| the Soviet players in the middle rounds were doing subtle
| not-right moves with the US #1. This forced the lead US
| player to put way too much effort into figuring out if it was
| some new line that he didn't know about and tiring him out.
| Then by the time he got to the final he was exhausted and
| confused.
| ceejayoz wrote:
| I'm not inclined to see that as _cheating_.
| thomasz wrote:
| Right, it's collusion.
| ceejayoz wrote:
| No? It's a technique that could readily be done by one
| person, and teams are allowed to strategize.
| Bluffing/deception is kosher in chess, just harder as the
| key elements of the game are all public.
|
| Before computers put an end to the practice, long games
| used to adjourn overnight.
| https://www.chess.com/terms/chess-adjournment
|
| > During adjournments, players could count on the help of
| other strong masters, called seconds. These seconds would
| analyze the position and tell the player what they should
| play when the game resumed.
| nyeah wrote:
| Agreed, it's not collusion if it's only done by one
| person.
| recursive wrote:
| That sounds like strategy, not cheating.
| fatbird wrote:
| In parallel to this (and Bobby Fischer explicitly accused
| them of this), the Soviet players had already decided who
| would be the champion amongst themselves, and subtly let
| that player win his matches so that he was fresh and well-
| rested when he ended up playing non-Soviet players.
| amdsn wrote:
| Getting any kind of information from a chess engine would be
| sufficient to gain an edge for a good player. Even something
| as simple as a nudge that there is a high value move in a
| position with no information about what the actual move is
| could be enough. Big chess tournaments tightly control phones
| and other devices for this reason. That's on a single-match
| level. On a tournament level there have been allegations of
| collusion where players will intentionally arrange their own
| matches to either be quick draws (to get a break to focus on
| other matches) or to give points to a designated player to
| help them win the tourney, Fischer famously accused Soviet
| chess players of doing this.
| giancarlostoro wrote:
| Makes sene! Thanks, I dont play much chess so its a bit out
| of my wheelhouse.
| fwip wrote:
| Getting tips from another person or a computer on what best
| move to make. This could be as simple as a compatriot in the
| audience giving you hand signals.
| michaelt wrote:
| _> I 'm just trying to figure out how you even cheat on
| chess,_
|
| You use a chess engine to tell you the best move - you can
| run a chess engine on a modern phone that will easily best
| the world's top human chess players.
|
| The simplest forms of this are things like: "play online,
| chess engine open in another window", "use your phone hiding
| in a bathroom cubicle" and "member of the audience follows
| your game with a chess engine and signals you somehow"
|
| There are also rumoured to be very subtle ways of doing this
| - like playing unassisted for most of the game, but an engine
| providing 'flashes of genius' at one or two crucial moves of
| the game.
|
| Major competitions have things like metal detectors and time-
| delay video feeds hoping to make cheating harder.
| kevin_thibedeau wrote:
| Future chess games will have to be played as Faraday cage
| matches. Two men enter, one man leaves.
| gosub100 wrote:
| This makes me want to cheat just as a technical
| challenge. Could I hide a computer in my hair? Could I
| ingest a capsule computer and communicate with it using
| the resonance of my teeth chattering? (No, I would not
| insert one in an inappropriate place).
|
| I'm sure it would be a downer that I cheated but it would
| do them a favor by saying: "look, you cannot stop it.
| Time for something new".
| zikduruqe wrote:
| You'd love NASCAR then.
|
| It's not really cheating in NASCAR, but rather, "it
| wasn't in the rulebook".
|
| Example - https://www.youtube.com/watch?v=GnZ4nBrp6mo
| omegaham wrote:
| Since even a phone has enough processing power to make
| Stockfish play better than a super-GM, the Faraday cage
| isn't enough to prevent, say, someone tapping the
| position into a computer on their person and feeling for
| some sort of vibration[1] in response. It takes very
| little information to represent a position, and
| commentators have pointed out that the minimum amount of
| information required to produce a decisive advantage is 1
| bit ("A winning move exists").
|
| [1] Yes, the ribald jokes have already been made
| tomku wrote:
| The vast, overwhelming majority of chess games are not played
| in front of cameras or even in-person. The accusation in the
| article was about online play, and specifically blitz which
| is played online even more commonly than slower formats of
| chess because moving quickly is easier for many people with a
| mouse than a physical board.
|
| The way people cheat online is by running a chess engine that
| analyzes the state of the board in their web browser/app and
| suggests moves and/or gives a +/- rating reflecting the
| balance of the game. Sometimes people run it on another
| device like their phone to evade detection, but the low-
| effort ways are a browser extension or background app that
| monitors the screen. The major online chess platforms are
| constantly/daily banning significant amounts of people trying
| to cheat in this way.
|
| Chess.com and Lichess catch these cheaters using a variety of
| methods, some of which are kept secret to make it harder for
| cheaters to circumvent them. One obvious way is to
| automatically compare people's moves to the top few engine
| moves and look for correlations, which is quite effective
| for, say, catching people who are low-rated but pull out the
| engine to help them win games occasionally. It's not that
| good for top-level chess because a Magnus or Hikaru or
| basically anyone in the top few hundred players can bang out
| a series of extremely accurate moves in a critical spot -
| that's why they're top chess players, they're extremely good.
| Engine analysis can still catch high-level cheaters, but it
| often takes manual effort to isolate moves that even a world-
| champion-class human _would not_ have come up with, and
| offers grounds for suspicion and further investigation rather
| than certainty.
|
| For titled events and tournaments, Chess.com has what's
| effectively a custom browser (Proctor) that surveils players
| during their games, capturing their screen and recording the
| mics and cameras that Chess.com requires high-level players
| to make available to show their environment while they play.
| This is obviously extremely onerous for players, but there's
| often money on the line and players do not want to play
| against cheaters either so they largely put up with the
| inconvenience and privacy loss.
|
| Despite all of the above, high-level online cheating still
| happens and some of it is likely not caught.
|
| Edit: More information on Proctor here:
| https://www.chess.com/proctor
| mft_ wrote:
| > It's not that good for top-level chess because a Magnus
| or Hikaru or basically anyone in the top few hundred
| players can bang out a series of extremely accurate moves
| in a critical spot - that's why they're top chess players,
| they're extremely good.
|
| Interesting; I thought I'd read that even the very best
| players only average ~90% accuracy, whereas the best
| engines average 99.something%?
| janalsncm wrote:
| Well accuracy is measured against the chess engine's
| moves so it would be 100% by definition.
| tomku wrote:
| Top-level players regularly are in the 90-95% range
| aggregated over many games, with spikes up to 98-99%. If
| you have 98 or 99% accuracy over the course of an entire
| game (which happens sometimes!), it's either very short
| or you had significant sequences where you were 100%
| accurate. If that happened in one of my games it'd be
| clear evidence I was cheating, if it happens in a Magnus
| game it's him correctly calculating a complex line and
| executing it, which he does pretty often.
|
| Edit: Even lower-level cheated games are rarely 100%
| accurate for the whole game, cheaters usually mix in some
| bad or natural moves knowing that the engine will let
| them win anyways. That's why analysis is usually on
| critical sections, if someone normally plays with a 900
| rating but spikes to 100% accuracy every time there's a
| critical move where other options lose, that's a strong
| suggestion they're cheating. One of the skills of a
| strong GM is sniffing out situations like that and being
| able to calculate a line of 'only moves' under pressure,
| so it's not nearly as surprising when they pull it off.
| kmike84 wrote:
| > whereas the best engines average 99.something%?
|
| To compute accuracy, you compare the moves which are made
| during the game with the best moves suggested by the
| engine. So, the engine will evaluate itself 100%, given
| its settings are the same during game and during
| evaluation.
|
| You get 99.9something% when you evaluate one strong
| engine by using another strong engine (they're mostly
| aligned, but may disagree in small details), or when the
| engine configuration during the evaluation is different
| from the configuration used in a game (e.g. engine is
| given more time to think).
| neaden wrote:
| Accuracy is a poor measure for cheating since better
| chess players will put you in a more complicated
| position. I'm not especially good but I've played some
| games with high accuracy just because I just did some
| book moves and the opponent makes a mistake. Accuracy was
| high but the correct moves were never especially hard to
| see.
| fsckboy wrote:
| reading your description of the "invasiveness" of
| chess.com's surveillance of high level tournament play, I
| realized that chess.com could issue their own anal probe, a
| sonar listening device to check that there aren't any other
| anal probes in use. finally! we can be assured of a good
| clean game played fairly from both seats!
| kevinmchugh wrote:
| Well that's one hole plugged
| vunderba wrote:
| Pulling a "hand of god" [1] in chess is unlikely to be as
| successful as it was in soccer.
|
| Cheating is as simple as having somebody feed you chess
| engine moves from a nearby laptop running stockfish.
|
| [1] https://en.wikipedia.org/wiki/The_hand_of_God
| rayng wrote:
| Magnus Carlsen (2021)
|
| "... But had I started cheating in a clever manner, I am
| convinced no one would notice. I would've just needed to
| cheat one or two times during the match, and I would not even
| need to be given moves, just the answer on which was way
| better. Or, here there is a possibility of winning and here
| you need to be more careful. That is all I would need in
| order to be almost invicible."
|
| https://www.youtube.com/watch?v=VcbHmHHwlUQ&t=313s
| tzs wrote:
| Just having someone who is following the game with a chess
| engine and who has a way to get a single message to you
| telling you that your opponent's last move was a serious
| blunder would be enough to give you a noticeable advantage.
|
| For example look at the position in this video [1] from a
| recent game on Chess.com between Hikaru Nakamura and Fabiano
| Caruana (the title of the video says Magnus vs Hikaru because
| the video covers 3 of Hikaru's games in the tournament).
|
| I linked to a spot in the video a little before the part
| where one simple message could changed the game because the
| host is explaining what Hikaru is going to be trying to do.
| Briefly, trading pieces off is good for Hikaru, and that's
| what he starts to do.
|
| You can see from the evaluation bar this Stockfish says he is
| slightly better.
|
| Then he plays Bg5 which looks like an easy way for force a
| pair of bishops off, continuing the plan. But look at the
| evaluation bar! It quickly swings from 0.2 in favor of white
| to 1.7 in favor of black. But black can only realize that
| advantage by playing RxN, a move that Fabiano did not even
| consider. He went on to lose the game.
|
| A prearranged signal from a confederate that meant "Hikaru
| just made a game changing blunder" would very likely have
| resulted in Fabiano seeing RxN. It's a move that many would
| spot if they were given the position as a puzzle and so knew
| there was a tactic somewhere.
|
| [1] https://youtu.be/acjI2KqQ0gI?si=qkfkL6i53UDcBOQd&t=752
| ourmandave wrote:
| The chess hustlers in parks and beachside tables will take a
| pawn and the piece next to it with slight of hand. Or nudge
| it to a worse square.
| gosub100 wrote:
| There's a YouTube video where he orders a match with someone
| and insists that they order brand new in box laptops and a
| locally hosted chess server (I think the hypothesis was testing
| if in person games were any different than online. The other
| player was in the same room). But they ran into technical
| difficulties when windows began auto-updates.
| Retric wrote:
| The underlying flaw in this analysis is it assumes ratings
| reflect actual performance in a given game. A long winning streak
| becomes far more likely if one of the players is part of several
| matches while tired, drunk, etc. Similarly a players peak
| performance is going to be higher than their ELO because that ELO
| includes games played under less ideal conditions.
|
| ELO is presumably more accurate for over the board games at
| tournaments where players bring their A game than low stakes
| online games where someone may be less engaged. That's IMO more
| worth testing.
| cortesoft wrote:
| This is basically an article describing why you can't just look
| at an event after it occurs, see that it has some extremely rare
| characteristics, and then determine it was unlikely to happen by
| chance.
|
| It is like asking someone to pick a random number between 1 and 1
| million and then saying, "oh my god, it must not actually be
| random... the chances of choosing the exact number 729,619 is 1
| in a million! That is too rare to be random!"
| JDEW wrote:
| "You know, the most amazing thing happened to me tonight. I was
| coming here, on the way to the lecture, and I came in through
| the parking lot. And you won't believe what happened. I saw a
| car with the license plate ARW 357. Can you imagine? Of all the
| millions of license plates in the state, what was the chance
| that I would see that particular one tonight? Amazing!"
|
| -Feynman, from Six Easy Pieces
| cortesoft wrote:
| Feynman is one of the best ever at explaining complicated
| concepts in ways almost everyone can understand. That is a
| very rare skill for the super intelligent to have.
| tehlike wrote:
| Agreed on Feynman, but not necessarily on the
| generalization that it being a rare skill to simplify
| things. When you understand a thing so well, you can
| simplify it enough.
| IAmBroom wrote:
| I think it also takes a certain humility of character
| (which can coexist with tremendous self-esteem and even
| ego; see Feinman, Richard for an example).
| almostgotcaught wrote:
| yea i always remember this when people put on their tinfoil
| hats about some rare event.
| wrsh07 wrote:
| Yeah tbh it doesn't really go into chess-specific stats either
|
| You could look at a bunch of other metrics to identify
| cheating: how many errors/perfect moves^ and whether that's
| within the usual range. How well were the opponents playing?
| Etc
|
| If you consider that Nakamura might have been having a good
| day/week, was already stronger than his opponents, and some of
| them may have had bad games/days, you can change something from
| "extremely unlikely" to "about a dice roll"
|
| ^ according to stockfish
| permo-w wrote:
| not really. this may be true for the average player, but as
| Magnus has explained multiple times, all he or another top GM
| would need to be near-unbeatable would be to check an engine
| in 1 or 2 critical positions per game. this essentially
| impossible to detect statistically. even if a cheater were to
| use an engine on every move, it would be trivial to just vary
| the engine used for each turn, vary the number of moves
| picked, sometimes play a slightly worse move to evade
| detection, etc etc
| alfiedotwtf wrote:
| What I don't understand is that Hikaru can visualise in his
| head 30+ moves ahead from both plays, and yet he's not
| better than Magnus?
| hinkley wrote:
| Is that bit in The Queen's Gambit about chess players
| coaching each other between matches complete bullshit? Or
| should one expect a player to occasionally play
| uncharacteristically when the stakes are high because they
| would seek out advice which skews their play?
|
| Also psychological games fall neatly into the scenario you
| describe. I play better and you play worse because I got into
| your head, or sent the noisy people to be across the hall
| from you instead of from me, so I slept like a baby and you
| didn't.
| omegaham wrote:
| The adjournments in The Queen's Gambit were rendered
| obsolete after chess engines became strong enough to be
| useful in analysis. The last year that they were permitted
| was 1996.
|
| Match play at the World Championship (where the two players
| play each other repeatedly for many games) involves a ton
| of inter-game coaching and work as each player's team goes
| over what went well, what went wrong, and how the next game
| should be approached.
|
| Round robin play in small fields also has a significant
| amount of preparation because the schedule is known in
| advance, so players will know whom they have to play the
| following morning and will prepare accordingly.
|
| I'm not comfortable saying that Hikaru does exactly 0
| preparation for 3-minute Chess.com blitz games, but it's
| probably pretty close to 0.
| kelipso wrote:
| This article feels like an illustration of how easy it is to
| fool top chess players. For example, if the accusation was
| against Hans Niemann, top chess players and their fans would be
| eating it up.
| raincole wrote:
| You can and you should.
|
| If you flipped a coin 100 times and all you got are heads you
| really should assume it didn't happen by chance.
| stack_framer wrote:
| Nope. A previous flip has no bearing on the next flip.
| vonneumannstan wrote:
| You can calculate the probability of having a fair coin and
| as N(Heads) increases that probability goes down. Each flip
| is indeed independent but the distribution of flips tells
| you something about the coin.
| IAmBroom wrote:
| We aren't predicting flips based on "a" previous flip.
| We're predicting them based on the set of ALL KNOWN
| previous flips, which allows a statistical model.
| Lerc wrote:
| ' _If you flipped a coin 100 times and all you got are heads
| you_ '
|
| By starting the sentence with if, you are selecting the
| occurrence to look at.
|
| If you said I am about to look at the results of this coin
| toss that happened yesterday, if it is all heads then I am
| going to assume it was not random, then you are making the
| claim before you have seen the results. You can still be
| wrong, but the chances of you being wrong is the rarity of
| the event.
| nyeah wrote:
| Yeah, but say 1,000 people each flipped a coin 10,000 times
| and one of them once got a streak of 29 heads out of 30
| flips. Can we assume anything then?
| emil-lp wrote:
| Your comment made me think of an interesting story and a
| funfact.
|
| During WW2, allies tried to guess the number of German tanks by
| observing the serial numbers on captured tanks.
|
| https://en.m.wikipedia.org/wiki/German_tank_problem If, say,
| the serial numbers are unique, and come in sequence, if the
| five first numbers you see are all less than 100, it's a far
| chance that there aren't produced 200 tanks. (Provided some
| assumptions, of course.)
|
| The funfact is that you get different results if you follow the
| frequentist or the Bayesian approach.
| edbaskerville wrote:
| The Bayesian results will depend on the prior. They use a
| uniform distribution over # tanks produced, in the limit of
| the distribution's maximum -> infinity. Is that reasonable?
| Something more constrained might be better, maybe a gamma-
| Poisson prior with gamma mean based on some plausible
| estimate of production rate.
|
| (The frequentist/Bayesian estimates should converge as you
| collect more observations.)
| paxys wrote:
| Not the same though because we aren't talking about random
| events. If a player with a significantly lower ELO than Hikaru
| got the same winning streak against the same tier of players
| then you could absolutely conclude that it was cheating.
| FuriouslyAdrift wrote:
| There are actually some freaky patterns in nature (including
| how people think) that can help identify fake data...
|
| https://en.wikipedia.org/wiki/Benford%27s_law
| lblume wrote:
| The article itself states that this is not really a pattern
| of nature, but just a feature of log-normal distributions
| that sometimes do occur naturally.
| macspoofing wrote:
| >This is basically an article describing why you can't just
| look at an event after it occurs, see that it has some
| extremely rare characteristics, and then determine it was
| unlikely to happen by chance.
|
| No. That's not it. In this case, if you properly control for
| all the factors, it turns out that the odds of Nakamura having
| that kind of a win-streak (against low-rated opponents) was in
| fact high.
| lcnPylGDnU4H9OF wrote:
| My favorite way to describe this is in the context of
| predictions. It's the difference between throwing a dart to hit
| a target and throwing a dart to paint a target around where it
| lands.
| aqme28 wrote:
| I'd be much more suspicious if his online performance didn't
| track with his professional over-the-board performance, where
| cheating would be much more difficult.
| m348e912 wrote:
| I thought this chass cheating story was going to be about Hans
| Niemann's (alleged) vibrating anal beads. I'm slightly
| dissapointed.
| abdulhaq wrote:
| Can anyone tell me why numbers in this article are being rendered
| higgledy-piggledy on my browser, Firefox / Windows 11?
| mechanicum wrote:
| It uses old style figures rather than lining, if that's what
| you mean by "higgledy-piggledy". See
| https://practicaltypography.com/alternate-figures.html#oldst...
| abdulhaq wrote:
| ta
| rprenger wrote:
| I think if Kramnik accuses someone of cheating it might actually
| drop the posterior probability that they cheated.
| ARandumGuy wrote:
| If you want a deep dive into chess cheating, including a lot of
| wild stories, Sarah Z put out an entertaining Youtube video [1] a
| couple of months ago that explores the concept. It's a long
| video, but well worth the watch.
|
| [1]: https://www.youtube.com/watch?v=ZtN-i-IkRWI
| srge wrote:
| Kramnik has proven himself a troll and did a lot of damage to the
| reputation of honest and otherwise wholesome people and this
| without credible proof at all. That those allegations persist
| under the form of news article is very unfortunate to those
| victims of his smearing.
| zahlman wrote:
| Being a "troll" connotes bad faith, i.e. not believing one's
| own accusations.
|
| From the footage I've seen of Kramnik, I think he does believe
| himself, and is just generally very "salty" about losing (as
| the kids say).
| NohatCoder wrote:
| While it is good to see some Bayesian statistics in use, I
| wouldn't in this case put so much emphasis on an exact calculated
| probability that he did or din not cheat, the prior in this case
| is simply too wishy-washy for that.
|
| The sound conclusion is that this is not evidence of cheating,
| but it is not evidence of the contrary either.
| univalent wrote:
| Kramnik went from chess champion who really came up with new
| lines in the Berlin defense, beating Kasparov at his peak: to now
| becoming a troll :(
| catigula wrote:
| A simple solution is to hold all chess matches in a SCIF.
| beepbooptheory wrote:
| There is probably 1000 hours of videos online of Hikaru talking
| through games, literally exhibiting his skill in full
| transparency. Hard for me to even understand what it would mean
| for him to cheat, his brain at times feels like the cheat.
| bluecalm wrote:
| >>The researchers note that there's a problem with this argument,
| too, as it violates the likelihood principle. This principle
| tells us the interpretation should only rely on the actual data
| observed, not the context in which it was collected.
|
| and then in the publication itself:
|
| >>The likelihood principle [Edwards et al., 1963] is a
| fundamental concept in Bayesian statistics that states that the
| evidence from an experiment is contained in the likelihood
| function. It implies that the rules governing when data
| collection stops are irrelevant to data interpretation. It is
| entirely appropriate to collect data until a point has been
| proven or disproven, or until the data collector runs out of
| time, money, or patience
|
| Surely there is a difference when you look at someone who played
| 46 games online in his life and scored 45.5 and when you look at
| someone who played 46000 games and scored 45.5/46 once.
|
| The difference is that Kramnik wasn't "collecting the data" but
| looked at the whole Nakamura's playing history and found a
| streak.
|
| Another example would be looking at coinflips and discarding
| everything before and after you encounter 10 heads in a row to
| claim you have solid evidence that the coin is biased.
|
| They are misapplying the principle here. If what they wrote was
| correct then someone claiming: "Look, Nakamure won 100 out of 100
| if you just look at games 3, 17, 21, 117...." would be proving
| Nakamura cheated if they applied methodology from the paper even
| assuming one in 10000 guilty players. Just because you can choose
| sampling strategy and stopping rules (what the likelyhood
| principle states) doesn't mean you can discard data you collected
| or cherry pick parts that support your hypothesis.
|
| How the data is collected is absolutely relevant and Nakamura is
| right to point it out.
| indigodaddy wrote:
| General statistical question. If we say extend the coin flip
| example distribution to say 10B times. Should/would we expect
| to see a streak of 100 or even 1000 in the distribution
| somewhere? Intuition alone tells me probably not for 1000 but a
| smallish chance for 100 (even if 10B in a row i would think a
| streak of 100 would be unlikely)
| steppi wrote:
| Your intuition's not bad. The expected value for the longest
| run of heads in N total flips of a fair coin is around
| log2(N) - 1 with a standard deviation that's approximately
| 1.873 plus a term that vanishes as N grows large. log2(10B) -
| 1 is approximately 32 and with that standard deviation, even
| a run of 100 in 10B flips is incredibly unlikely. For more
| info see Mark F. Schilling's paper, "The Longest Run of
| Heads" available here
| https://www.csun.edu/~hcmth031/tlroh.pdf.
| xrisk wrote:
| That's a cool result, thanks for the link!
| indigodaddy wrote:
| Neat! I guess this is a common thing to wonder about :)
| sobiolite wrote:
| > Nakamura responded to Kramnik's allegations by arguing that
| focusing on a particular streak while ignoring other games was
| cherry-picking. The researchers note that there's a problem with
| this argument, too, as it violates the likelihood principle. This
| principle tells us the interpretation should only rely on the
| actual data observed, not the context in which it was collected.
|
| I don't quite understand this objection? If I won the lottery at
| odds of 10 million to 1, you'd say that was a very lucky
| purchase. But if it turned out I bought 10 million tickets, then
| that context would surely be important for interpreting what
| happened, even if the odds of that specific ticket winning would
| be unchanged?
| AlecBG wrote:
| Or similarly I flip a coin a thousand times, but only tell you
| when it's heads and don't tell you how many flips I did.
| gus_massa wrote:
| I agree. The problem when you look only at some "interesting"
| data even has a name https://en.wikipedia.org/wiki/Look-
| elsewhere_effect
| bregma wrote:
| Or if Bob Barker has opened door number 3 and there's a goat
| behind it.
| sema4hacker wrote:
| Monty Hall.
| oersted wrote:
| Indeed. I'd say that the issue is that they are misinterpreting
| the word "collecting". The principle is true if you are
| collecting or observing data live, but this data was collected
| long ago and with a much wider scope: when the games were
| recorded.
|
| What they are doing here is _sampling_ the data after the fact,
| and obviously one needs to take a uniformly random sample of a
| dataset for any statistical analysis done on it to be
| representative.
| bitshiftfaced wrote:
| I believe they're speaking within the scope of the Bayesian
| analysis. We _could_ interpret games outside of the winning
| streak as evidence to whether he 's a cheater or not. Instead,
| I believe they are looking at the question of "given this
| winning streak in particular, what's the probability of him
| cheating in this set of games"?
|
| They start with a prior (very low probability), I'm assuming
| they use the implied probabilities from the Elo differences,
| and then update that prior based on the wins. That's enough to
| find the posterior they're interested in, without needing to
| look outside the winning streak.
| nextaccountic wrote:
| The issue here is that the events are not independent.
| Because of that, the other games surely provide useful data
| jonahx wrote:
| His performance in games outside the streak is relevant to
| the prior of his being a cheater, which in turn is highly
| relevant to how calculate p(cheater | this streak).
| Archelaos wrote:
| > "given this winning streak in particular, what's the
| probability of him cheating in this set of games"
|
| I think the problem lies in the antecedent. Given all chess
| tournaments played, how often would we observe such a winning
| streak on average? If the number of winning streaks is near
| the average, we have no indication of cheating. If it is
| considerably lower or higher, some people were cheating (when
| lower, than the opponents).
|
| Then the question is, whether the numbers of winning streaks
| of one person are unusually high. If we would for example
| expect aprox. 10 winning streaks, but observe 100, we can
| conclude that aprox. 90 were cheating. The problem with this
| is that the more people cheat, the more likely we are to
| suspect an honest person of cheating as well.
|
| Again, this would be different if the number of winning
| streaks for a particular person were unusually high.
| Simulacra wrote:
| Tangently related, reading this I couldn't help but think about
| the biological passports for professional cyclist. It tracks
| blood and other values overtime, so that anomalies will jump out.
| rybosworld wrote:
| Here's a better question:
|
| What are the odds that a cheating accusation accurately
| identifies an instance of cheating?
|
| I don't say this lightly: Kramnik very likely has some sort of
| untreated psychiatric disorder. He is effectively a lolcow in the
| chess community because he regularly (as in, almost daily)
| accuses much better chess players of cheating.
|
| It's honestly a bit undignified to treat his accusation against
| Nakamura as anything other than a man yelling at the sky.
| bombcar wrote:
| There's some strange inverse, where situations we KNOW are rife
| with cheating have few accusations thereof (bike racing
| perhaps), and those that are almost certainly very rare may
| also have few accusations (because it's rare).
|
| Sometimes you have to treat any accusation as "real" just to
| keep the cheaters at bay. (Cheating at online bridge is
| rampant, and cheating at bridge competitions was and perhaps
| still is fraught with many scandals).
|
| It's often common that the cheaters really ARE very good
| players - they're just looking for less work, not a goal they
| couldn't obtain otherwise.
| Scarblac wrote:
| I find it counter intuitive that the frequency of cheating
| matters. It's not something that happens randomly, people choose
| to. And if the #2 in the world decides to cheat it may be for
| different reasons than other players.
|
| But, of course he doesn't. He streams all his games and gives
| constant stream of consciousness commentary. If you can explain
| your top level moves live with seconds per move, you aren't
| cheating.
| lblume wrote:
| > It's not something that happens randomly, people choose to.
|
| In Bayesian analysis, probability does not refer to the long-
| term frequency but instead to the subjective credence given to
| the event. Otherwise the probability of any one-off event would
| be undefinable. Therefore it follows that you need to have a
| prior over possible hypothesis in order to update your beliefs
| systematically according to the laws of probability theory. If
| it were known that Hikaru had cheated in the past, but
| typically does not, we might use a different prior (e.g. a
| Laplacian prior in this case); if we knew cheating to be
| dependent on some other measurable variable (e.g. the emotional
| state of the player), we would incorporate this into our
| evidence.
| siegecraft wrote:
| It's frustrating that their entire analysis is based on the claim
| that cheating occurs in maybe 1 out of 10,000 games; they got
| this from a quote in an interview with the deputy president of
| the World Chess Federation after he had been beaten in a charity
| match by someone who admitted cheating. To their credit they also
| ran the analysis assuming cheating is 1/500 and the odds rose to
| 7%. I suppose it makes sense that they are merely rebutting the
| accusations based on the same methodology but it's still
| frustrating.
| cortesoft wrote:
| Part of Bayesian analysis is choosing your prior probabilities.
| Luckily, with enough data the priors become less and less
| important, but you do need to choose them.
| ChrisArchitect wrote:
| Title is: Did a US Chess Champion Cheat?
|
| why was it changed? This isn't a 'recent' story, it's from
| January.
| anteloper wrote:
| This leaves out the extremely important detail that many if not
| all of these 46 games, Hikaru was actively streaming on Twitch.
|
| The actual chess community's takeaway from this (if consensus is
| important to you) is that Kramnik (the accuser) has lost it a
| bit.
| bloodyplonker22 wrote:
| Anyone who does competitive gaming or sports knows that the
| greatest compliment is to be called a hacker or cheater when not
| actually cheating.
| TZubiri wrote:
| > Kramnik pointed out the statistical improbability of Nakamura's
| streak and stated that such a winning run would require the chess
| prodigy to play at a level higher than his current Elo rating (an
| estimate of a player's skill level based on their historical
| play).
|
| While ELO ratings are a probabilistic model, who said wins and
| losses have to be randomly distributed, there can be bad days and
| good days, for example if you haven't slept or if you are at the
| peak combination of study and cognitive, say because you are well
| rested on a monday and have been studying on the weekend.
| mwkaufma wrote:
| Once against, (ab)using Bayes is the favored tool for Technical
| Boys when they want to bullshit.
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