Tag Archive: chess


(Submitted by Skepticality personality and friend of the blog Bob Blaskiewicz.)

What are the odds? I mean, they must be CrAzY!!!!
Bob 🙂
Two players die at world chess event in Norway
Competitor dies in the middle of a match during Chess Olympiad in Norway and another is found dead in hotel room
By Esther Addley

The most prestigious international tournament in chess, at which the world’s top players compete alongside amateurs to win honours for their country, has ended on a sombre note after two players died suddenly within hours of each other, one while he was in the middle of a match. Hundreds of spectators attending the 41st Chess Olympiad in Tromsø, Norway, and countless others watching live TV coverage on Norway’s state broadcaster, reacted with shock after Kurt Meier, 67, a Swiss-born member of the Seychelles team, collapsed on Thursday afternoon, during his final match of the marathon two-week contest. Despite immediate medical attention at the scene he died later in hospital.Hours later, a player from Uzbekistan who has not yet been named was found dead in his hotel room in central Tromsø. Norwegian police and the event’s organisers said on Friday they were not treating the deaths as suspicious.

“We regard these as tragic but natural deaths,” said Jarle Heitmann, a spokesman for the Chess Olympiad. “When so many people are gathered for such a long time, these things can happen.

The Olympiad involved 1,800 competitors from 174 countries, accompanied by more than 1,000 coaches, delegates and fans.

The event sees players compete in national teams over 11 rounds, often playing matches that last for up to six hours, and claims a worldwide online audience of tens of millions.

There were brief scenes of panic in the hall after Meier’s collapse, when spectators reportedly mistook a defibrillator for a weapon. Play was briefly suspended before his death was marked with a minute’s silence during the closing ceremony.

While the causes of the two men’s deaths are still unknown, they will raise questions about the mental and physical stress that tournaments place on players.

Meier is not the first player to die in the middle of a match; in 2000 Vladimir Bagirov, a Latvian grandmaster, had a fatal heart attack during a tournament in Finland, while in the same year, another Latvian, Aivars Gipslis, suffered a stroke while playing in Berlin from which he later died.

One of Australia’s leading players, Ian Rogers, retired abruptly from chess in 2007, saying he had been warned by his doctors that the stress of top-level competition was causing him serious health problems.

Tarjei J. Svensen, a reporter for chess24.com who attended the Olympiad, said the event had a reputation for heavy drinking. “There are two rest days during the competition, and particularly the night before the rest days there tends to be a lot of drinking,” he said.

A favourite attraction for delegates was the now-legendary “Bermuda party”, he added, hosted at each Olympiad by a member of the Bermudan delegation.

The Olympiad was big news in Norway, with the state broadcaster, NRK, carrying hours of live coverage each day, and the country’s government paying 87m kroner (£8.5m) for the privilege of hosting the event.

Last week the women’s team from Burundi were disqualified after failing to show up for their round six and seven matches; they remain unaccounted for, Heitmann said on Friday.

“It has been an eventful Olympiad, certainly,” said Svensen.

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Below are the extended notes provided by contributing editor Mark Gouch for use in Skepticality Episode 251. Mark is a wastewater treatment system operator and engineer living in Smithtown, NY (Long Island). He started to become interested in coincidences after recognizing the series of events that conspired to get him employment on Long Island many years ago. Two of Mark’s recommended books include “The Drunkard’s Walk: How Randomness Rules Our Lives” by American physicist and author Leonard Mlodinow, and “The Hidden Brain: How Our Unconscious Minds Elect Presidents, Control Markets, Wage Wars, and Save Our Lives” by Shankar Vedantam.

Take a look and leave your comments below. Also, please be sure to listen to the podcast for our own hilarious commentary.

A sad story, and surely it must have been a shock to those involved in the chess tournament. Well, we do not have a lot of information about the cause of death of the two men, so that limits what we might say about the probability. The best we can do is a very general estimate of the odds of the death of any person out of a thousand random persons. According to the ECOLOGY Global Network ™ web site, as of 2011 the global daily death rate was about 151,600 deaths per day. And in round numbers world population is about 7.3 billion.

So it would seem we should estimate the odds of one person out of a thousand at any conference, or any group of a thousand people should be somewhere around 151,600/7,30,000,000  * 1000= 0.0215, or about 2.15%. The odds of two persons in the group dying would be 0.0215 * 0.0215=0.00046, or about 0.046%. I think most people like to think of odds in terms of per million. So 0.0046% odds is 46,200 per million. This means that for every million conferences, meetings, etc. that have about a thousand persons in attendance, there would be over 46,000 of those events.

(Submitted by Skepticality listener and friend of the blog Christopher Brown.

Hi all:

My son, Ethan Brown performs a Mental Mathematics stage show. A few months ago, he developed a new piece for his act. It’s a version of an old presentation puzzle known as The Knight’s Tour.

Traditionally, performers have allowed audience volunteers to select a square on a Chessboard. The performer then begins on that square and theoretically moves a knight around the board using only legal knight moves (which are “L” shaped). The goal is to land on every single square on the board without landing on any square twice.

Ethan adds an additional twist to this trick by allowing the audience to also select the final square on which the knight must land, finishing the puzzle.

Since debuting this new trick, he has had a chance to perform it 5 times. 3 out of those five times, the two audience members selected the exact same two squares (only they were reversed in one of those times). Our back of the envelope calculations place the Mathematical odds at 1 in 107,374,182, though I suspect something else might be going on here. We have video of 2 of the performances if you’d like to see it. Could there be something psychological that causes people to gravitate to these squares much like people often pick “Ace of Spades” when asked to randomly think of a card?

I have attached photos of the three final Knight’s Tours. Note where the numbers 1 and 64 are.

KnightsTour1

KnightsTour2

KnightsTour3

Thanks! Let me know if you have any questions at all.


Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 244.  Take a look and leave your comments below. Also, please be sure to listen to the podcast for our own hilarious commentary. Also, visit Barbara’s blog.

These notes are a bit dense for the podlet, but maybe you can use the story and just skip most of the math.

+++++

First, let’s assume that the choice of square is completely random in all cases.

We are not particularly interested in the odds that the audience would choose those squares because it’s not the squares themselves that are interesting. It’s the fact that the audience chose the same squares the second time Ethan performed the trick. Therefore, we are given the squares by the first audience and we want to calculate the probability that the second audience would choose those particular squares.

To calculate the odds of choosing those particular squares, we must first note the odds for each, which are pretty easy. The odds of choosing the first square are 1 in 64, or .015625. The odds of choosing the second square are 1 in 32 (since you are limited to only white squares and all white squares are available), or .03125. The odds of choosing both is:

.015625 x .03125 = .00048828125 or 1 in 2,000

1 in 2,000 is the probability that the audience will choose the same squares on the second round that it did on the first round.

The third instance is a bit different because, although the audience chose the same squares, the starting and ending squares are backwards. The calculation is partially the same, but if we allow either square to be the starting square, we are now asking a different question. We now want to know the probability of choosing that specific black square to start and white square to end, or that particular white square to start and black square to end. So, we start with the probability of each scenario, which we know to be about 1 in 2,000, then double it (it is not possible to choose both, so there is no joint probability to subtract). So, the probability of choosing either the same squares or the same squares in reverse on any subsequent game is about .00098 or about 1 in 1,000.

Since each time Ethan performs this trick, there is about 1 in 1,000 chance that the audience will choose those same squares as start/end points, the probability that it would happen on the 3rd, 4th, or 5th time that he performed it is about 3 in 1,000, or .003.

So, taken as a whole, the probability of the audience repeating the first (exact) choices on the second performance and choosing the same squares on one of the three subsequent performances is about .0000015, or 1.5 in a million. So not quite one in a million…

But that is all assuming that the choices were random. I saw nothing in Ethan’s posture or delivery that would suggest any given square as a starting point. However, we do know that human beings don’t do anything at random. I doubt that anyone has conducted studies to determine which squares someone is likely to choose if they are in this particular situation, but I think it is fairly safe to say that they are at least twice as likely to choose squares in the middle of the board than on the edges. I would be interested to find out if that is true, but let’s assume that number is accurate.

That changes the entire game.

We could simply double the probability of choosing those same squares in the second performance, but that wouldn’t give us the whole picture. Now we have to consider the probability of choosing those squares in the first round, because it is no longer a uniform distribution.

If we consider that someone is twice as likely to choose a square that is not on the edge, the probability of choosing that particular square is now .02, or 1 in 50. Likewise, the probability of choosing an ending square that is not on the edge is about 1 in 25. So the probability of choosing those particular beginning and ending squares is:

.02 x .04 = .008 or 1 in 125.

And now the probability of choosing the same squares, with either as the starting square, is about 2 in 125.

And that makes the probability of this scenario about 1 in 31,250.

But I think it is worth noting that the probability of those two squares being chosen at any given performance is independent of the outcome of other performances. It ranges from 1 in 1,000 to 2 in 125, which isn’t exactly “crazy”. But if it keeps happening, I’m going to think seriously about setting up a betting pool.