Draw Fixing: An Official Study

First topic message reminder :

The link below shows a talk by an Estionian researcher Katarina Pijetlovic, giving an exposition on draw fixing at a Corruption in Sport Symposium in Koln.


Katarina's talk starts at around 13 minutes:

http://www.livestream.com/playthegame_dshs/video?clipId=pla_44809e94-aa04-46c7-9f1e-35b212ba9d46


She examines the pattern of draws at slam tournaments (French Open was not part of the study) between 2007-2011, drawing the conclusion that ITF organised draw fixing on behalf of Nike seeing that Djokovic fell in Federer's half of the draw statistically virtually impossible 12 out of 12 times.

Roland Garros was not taken into the study as it showed a healthy 50/50 pattern.



Interesting facts, e.g. I didn't know that seeds 3 and 4 are drawn by hand unlike all the other seeds/players that are computer drawn.
Draws are apparently public and televised, but not really accessible anywhere on Youtube.

To me, the most blatant example of draw fixing was the Isner Mahut match played in the first round last year ON COURT 18, just like at the record breaking match the year before!!!


Katarina did the research hoping it would interest sports journalists and encourage them to contact the players and ITF.


So far nothing came out of it.

Have a look with an open mind and share your thoughts.

Please, everyone. This really is not about bashing any player. For eg, if this is true, it might be that even Federer benefited from not having to play Murray. Or perhaps it is Murray who benefited from not having to play Federer, The same is true for Djokovic and Nadal. The players might not even know about this. But as fans, when we see a strange pattern like this, we should at least sit up and take notice, leaving aside our player allegiances When you realise that this is not about a particular player but rather about the sport as a whole, many of the posts above defending certain layers will become redundant and together as a group, we will begin to see what we haven't till now.

Sure as this whole thing is not about players, it's about money, sponsorship and what fans expect and are ready to pay to watch. Obviously TV/Media is involved here as well with their millions on broadcasting rights.

I mean who wanted to see a Murray-Djoko or Nadal-Murray final in GS 3-4 years ago? Their family members probably, but certainly not organizers or TV companies. Fed-Nadal were Kings and they got served & hyped nicely by all involved in this every increasing money spinning machine called Tennis.

Lydian has this correct on the first page. The identity of the players cannot be used as evidence of draw rigging because the draw is constructed around ranking. In other words, the random element is not who players are but what their ranking is.

It's easier to think of in reverse. For example, let's say the US Open rigged the draw between 2009 and 2011 and put seed 1 with seed 3 every time. That would have put Djokovic against Murray in 09, against Nadal in 10 and against Federer in 11.

Even though the outcome is three different players, it is the same draw each time

Just as a mixture of opponents does not prove the draw to be 'honest', nor does having the same opponent prove it to be rigged.

Tenez wrote:

laverfan wrote:I would suggest reading some high-school statistics and pseudo-random number generation methods.

Yes time to reopen your old books.

A series is something we define at will and why we pick a series brings credibilty to the find. It coudl have been the last 10 Wimbledons or the USO between 1920-39. we are free to pick what we want. Here the series picked (2008-11)is credible for the following reasons:

Why did you not pick the explosion of Krakatoa to be part of this series? Do you understand the meaning of the word 'arbitrary'? Why not pick the date of monsoons in the Bay of Bengal and the 2007-2011 W draw?

Tenez wrote:1 - before 2007, we did not know how good was Djokovic and were not sure whether he woudl reach the semis regularly, so clearly in Jan 07 Djoko was as feared as PHM and less than Robredo so no need to work out which side he will be in the draw. However by the end of 2007, we knew he was a very good player as he had reached FO semi, Wimbleodn semi and USO. That is why 2008 makes perfect sense. In fact we coudl even argue that the USO may have fixed the draw as early as 2007 which makes the series, not 12 but 13. hence 1 in 8.2k (huge hazard!)

Again, picking your facts to fit a theory.

Tenez wrote:2 - and most convincing maybe is that it's clearl that before 2008 Nadal's team or Nike (Both most likely) realised that Djoko was the up and coming boy and that Nadal had already trouble with him. Nadal had already experienced his first loss from Djoko and that was on HC! Nadal had only managed to win Djoko outside clay on a RR at the masters in China when clearly DJoko did not try that year and did not win a single match. The WImbleodn match was the clear signal that Djoko was going to be trouble for Nadal and Djoko could only improve from there.

2007 Tennis Masters Cup
China Hard RR Nadal, Rafael
6-4, 6-4 Stats
2007 ATP Masters Series Canada
Montreal, Canada Hard S Djokovic, Novak
7-5, 6-3 Stats
2007 Wimbledon
Great Britain Grass S Nadal, Rafael
3-6, 6-1, 4-1 RET Stats
2007 Roland Garros
France Clay S Nadal, Rafael
7-5, 6-4, 6-2 Stats
2007 ATP Masters Series Rome
Italy Clay Q Nadal, Rafael
6-2, 6-3 Stats
2007 ATP Masters Series Miami
FL, U.S.A. Hard Q Djokovic, Novak
6-3, 6-4 Stats
2007 ATP Masters Series Indian Wells
CA, U.S.A. Hard F Nadal, Rafael
6-2, 7-5 Stats
2006 Roland Garros
France Clay Q Nadal, Rafael
6-4, 6-4 RET Stats

Federer had lost to Nadal in Miami 2004. Why not use 2004-2011 for you study? . Federer lost to Canas twice, Nalbandian twice. Go look at the draws and see after the two loses where Nalbandian ends up.

Tenez wrote:3- in 2007 we were still under the Federer magic spell but more and more fans wanted to see Fedal's final outside clay. Wimbledon in 2007 may have been deprived of that had Djoko not been injured. They knoew Federer could handle Djoko but Nadal was struggling to do it outside clay.

So what?

Tenez wrote:4 - Why leaving the FO out? I suspect the student who did it didn't quite know or did not want to appear so radical to an audience who doesn;t maybe understand tennis as much. But of course by 2008, Nadal had won 3 FOs and the French wanted Fed to win anyway so it is very unlikely they would have made things easier for Nadal. Besides they claim the computer is doing the draw and clearly that brings us closer to a 50/50 rate.

Because it does not fit someone's theory.

Tenez wrote:So like it or not the 2008/11 series is a very good one. There is still a chnace it's pure hasard but that chance is 1 in 4k if not 1 in 8k. In probability terms....it's a very small chance. Add the fact they also twick the draw of the first rounds, then the chance it's down to chance is virtualy nil.

You have no mathematical leg to stand on. Hence your choice of arbitrary data. Perhaps you should also look at the astrological charts when the draws were made to find other common factors.

HM Murdoch wrote:Lydian has this correct on the first page. The identity of the players cannot be used as evidence of draw rigging because the draw is constructed around ranking. In other words, the random element is not who players are but what their ranking is.

It's easier to think of in reverse. For example, let's say the US Open rigged the draw between 2009 and 2011 and put seed 1 with seed 3 every time. That would have put Djokovic against Murray in 09, against Nadal in 10 and against Federer in 11.

Even though the outcome is three different players, it is the same draw each time

Just as a mixture of opponents does not prove the draw to be 'honest', nor does having the same opponent prove it to be rigged.

I don't follow your reasoning. You base your thinking on the fact that draws are based on ranking but the fact is regardless of the ranking, it's 12 out of 12 for Fed/Djoko. If they wanted to rig draws, they would look at who plays who not 1/3s 2/4s.

I am sorry but this doesn't add up.

H M Murdoch, unfortunately that doesn't make the draw above suspicion. It is equally puzzling that whenever Federer was 1 and Djoker 3, 1 played 3. And when he was 1 and Djoker 4, 1 played 4. When the rankings changed, the draw changed with it. 12 times! Yours is the most commonly cited defence, and it is completely erroneous. It would have made sense if the draws were done months in advance before anyone knew the seeding, but not if the draws are done after the seeding is known!

LF - You have lost it once again. There is nothing arbitrary in picking the period Djoko and Murray mature and can be a threat to Federer and Nadal....not over one year or 2 but over 4 years!!!!

Frankly, you smileys make more sense that your text nowadays.

Tenez, exactly. I've heard this defence so many times and it really doesn't make any sense. Unfortunately, it's one of those wrong arguments which seem plausible, so people buy it.

Laverfan, you say this is arbitrary data. Why is it arbitrary data when it covers all non-clay slams over a period of 4 years. Please do explain! It doesn't make sense to ask for more data to be included. If someone spots a very strange trend in 4 years of data, are you going to ask him to include more years when the trend wasn't there. I just don't understand why a 12/12 occurrence is deemed insufficient. Adding more data isn't going to change these data points.

Tennisanorak wrote:H M Murdoch, unfortunately that doesn't make the draw above suspicion. It is equally puzzling that whenever Federer was 1 and Djoker 3, 1 played 3. And when he was 1 and Djoker 4, 1 played 4. When the rankings changed, the draw changed with it. 12 times! Yours is the most commonly cited defence, and it is completely erroneous. It would have made sense if the draws were done months in advance before anyone knew the seeding, but not if the draws are done after the seeding is known!

Exactly. I am puzzled by some reasoning here.

It's like M4C saying that there is as much chance that TTTTTTTTTTTT than THTHHTHHHTTT. It's correct! Just that it happened that THTHHTHHHTTT was exactly what was needed to have 12 times Djoko play Federe. Less than a chance in 4k!

Do people even realise how unlikely a 1 in 4000 chance is, btw? This is like asking someone to think of a number between 1 and 4000 without telling you and your guessing it right in your first chance.

Tennisanorak wrote:Laverfan, you say this is arbitrary data. Why is it arbitrary data when it covers all non-clay slams over a period of 4 years. Please do explain! It doesn't make sense to ask for more data to be included. If someone spots a very strange trend in 4 years of data, are you going to ask him to include more years when the trend wasn't there. I just don't understand why a 12/12 occurrence is deemed insufficient. Adding more data isn't going to change these data points.

Is the FO a separate event? Does it not occur as part of the 'slam' series?

One can pick just the USOs, like ESPN did, and prove their 'pet' theory? The longer the same #1-#4 at the top, the more likely that the draws will have the same two match-ups. Do you agree?

Why non-clay slams only?

Exactly, Tenez! Brilliantly put. The specific combination required to have Djoker and Federer play 12 times happened. Incredible. At least if it is 12 heads in a row, one could say it was a biased coin. Any other sequence which turned out exactly the way you wanted it beforehand is even more puzzling.

Tennisanorak wrote:Do people even realise how unlikely a 1 in 4000 chance is, btw? This is like asking someone to think of a number between 1 and 4000 without telling you and your guessing it right in your first chance.

There are 365 days in a year? How many birthdays and people born on the same day? Laver, Sampras and Federer are all August born? That is a series too. Why not consider an ITF conspiracy to have August-born slam champions. You keep mentioning 1/4000, but each slam is a discrete event. The arbitrariness of the series is what the argument is about.

Tennisanorak wrote:Exactly, Tenez! Brilliantly put. The specific combination required to have Djoker and Federer play 12 times happened. Incredible. At least if it is 12 heads in a row, one could say it was a biased coin. Any other sequence which turned out exactly the way you wanted it beforehand is even more puzzling.

Do you know how many times Laver-Rosewall played each other?

While the pattern relating to the draw for the semi finals of the grand slams is indeed noteworthy, for me the more interesting statistical finding is the one relating to the 'big two' and their draws in earlier rounds of the US Open.

I have always thought it an oddity that despite the potential for a 'draw of death' where a top player faces a highly ranked or up and coming opponent just outside of the top 32 in the first round or two this invariably never occurs; in fact never even gets close to occurring.

What we witness instead is the usual 'lamb to the slaughter' fare of a top seed on Ashe mauling a journeyman or qualifier, in what tends to resemble a rather protracted and elaborate practice session.

For the non-clay slams only part, it is clear that the relative strength of players is different on clay than on the faster courts. So that is obvious.

What would have been supicious is removing just one or two years from each of the slams. That would have been arbitrary; this most definitely is not. In fact, if anything, it strengthens the theory.

Just think- if the AO had to be removed and the USO had to be included, there is no hypothesis that can justify that. In this case, we most certainly have a hypothesis.

As for your question,

"The longer the same #1-#4 at the top, the more likely that the draws will have the same two match-ups. Do you agree?"

No, I do not think it makes that much difference if the same two match-ups have to happen so many times in a row. Getting 12 consecutive heads is very unlikely even if you get to toss say 24 times (6 years in tennis grandslam terms). Show me another instance from the past where the same two layers (prominent ones, not random ones) were drawn to play each other even say 9 times in a row. You're obviously going to reply by saying that it is impossible to comb through all previous years' data. While that is true, it doesn't invalidate this particular study.

I love this thread!

Statistical analysis, mathematical posturing, conspiricy theories, match fixing... It all leads to one thing. Nadal is using the ATP tour as a training ground. Somewhere to hone is vast political and manipulative skills. He is just toying with his fellow players, tournament officials, tournament owners and tennis fans. It is obvious that he will not stop at controlling the ATP tour. His dastardly plan must be to control the world...

At least here on 606v2 we can see right through him. But how do we stop such a powerful figure?

Here is a h2h that needs to considered and this 12-12 theory is sheer nonsense.

http://www.atpworldtour.com/Players/Head-To-Head.aspx?pId=L018&oId=C044

or this one...

http://www.atpworldtour.com/Players/Head-To-Head.aspx?pId=L018&oId=M047

Laver, Sampras and Federer are all August born?

>>> Okay, let us calculate probabilities here.

The probability of Sampras being born in the same month as Laver is 1/12 and that of Federer being born in the same month is 1/12. So the probability of this is 1/12 * 1/12 or 1/144 which is nowhere near 1/4000.

More importantly, Federer, Sampras and Laver is an arbitrarily selection. If it had been the top 3 most slam-winning champions, then yeah this would have been a coincidence. You are just choosing any 3 of the tennis greats. This makes a big difference.

I fail to see the same arbitrariness when the players involved are the specific match ups we have been most interested in for decades.

Which is why i said in an earlier post that if the study had been about Berdych and Fish meeting 6 times in a row, no one would have bothered.

HMH absolutely.

I tried making the same point myself but the conspiracy theorists looking for a smoking gun seem unable or unwilling to accept they should be looking at the patterns 1 vs 3, 2 vs. 4 against 1 vs. 4 2vs. 3 rather than going by the name as not each player was the same seed for each draw.

It' isn't exactly rocket science and here are the results since 2008 through to the end 2011. I didn't include the French Open but then again neither did the researcher (shoddy science indeed!):

1 vs. 4 and 2 vs. 3 a total of 7 times

1 vs. 3 and 2 vs. 4 a trotal of 5 times

Now ANY kind of statistical test you apply to that would suggest that's a random result for 12 independent events.

As a control I also tossed a £2 coin a total of 12 times and here are the results:

heads - 4

tails - 8

These results indicate I'm more biased in tossing a coin than the draws themselves.

IN CONCLUSION THE FACT THAT THESE ALWAYS SEEMS TO PLACE DJOKOVIC IN THE SAME HALF AS FEDERER IS AN ANOMALY. PERIOD!!!!!

Do you know how many times Laver-Rosewall played each other?

>>> Completely irrelevant, Laver fan. I really think that you're digressing from the topic of discussion here.

laverfan wrote:Here is a h2h that needs to considered and this 12-12 theory is sheer nonsense.

http://www.atpworldtour.com/Players/Head-To-Head.aspx?pId=L018&oId=C044

or this one...

http://www.atpworldtour.com/Players/Head-To-Head.aspx?pId=L018&oId=M047

did you have breakfast yet?

Unfortunately, newballs has made the same mistake that Tenez and I have pointed out earlier. It is not 8 heads and 4 tails. It is a specific sequence of 8 heads and 4 tails.

Say HHTHTHHTHHTH.

Now let me see you generate this with 12 coin tosses. All the best! This could take you days!

Tennisanorak wrote:Do you know how many times Laver-Rosewall played each other?

>>> Completely irrelevant, Laver fan. I really think that you're digressing from the topic of discussion here.

It is a series, correct? How is this a digression? You are perfectly willing to consider 12 occurrences as a 'series' but not a 142-event (79-63) as series?

spdocoffee wrote:
I have always thought it an oddity that despite the potential for a 'draw of death' where a top player faces a highly ranked or up and coming opponent just outside of the top 32 in the first round or two this invariably never occurs; in fact never even gets close to occurring.

Indeed! but this should reinforce the idea that the semis can be fixed as what can be done for the first round could easily be done for later rounds.

The chance of Isner playing Mahut in the first round of the following year of their Wimbledon epic was 1 in 96. Everybody was suspicious! now imagine 1 in 4096!

Spdcoffee- yeah, that's true as well. Hawk eye, please read my earlier post about how this is not about any specific player. If this had been observed in tournaments where Agassi and Sampras played, I would have made the same remarks. I am a fan of both of those players. This is about the sport, not about any player. Why do supposedly random draws throw up such results.

Say football semifinals were randomly drawn, and say England, Germany, France and Spain were the top 4 in every tournament. If England and Germany were drawn to play each other 12 consecutive times, would nobody have found it strange? Unbelievable!

Laverfan, what is the trend you spotted in laver- Rosewall matches? I'm all ears.

Statistics are like a drunk with a lampost: used more for support than illumination.
---Sir Winston Churchill

That's right, Henman Bill. We shouldn't notice even if Federer and Djokovic are drawn to play each other 50 times in a row, in every Masters series and Grand slam they play for years! Thank you for clarifying this!

newballs wrote:HMH absolutely.

I tried making the same point myself but the conspiracy theorists looking for a smoking gun seem unable or unwilling to accept they should be looking at the patterns 1 vs 3, 2 vs. 4 against 1 vs. 4 2vs. 3 rather than going by the name as not each player was the same seed for each draw.

IN CONCLUSION THE FACT THAT THESE ALWAYS SEEMS TO PLACE DJOKOVIC IN THE SAME HALF AS FEDERER IS AN ANOMALY. PERIOD!!!!!

Newballs. You are a smart guy! So please think a bit. just a bit!

If you and I want to rig a draw, we are not going to do it so 1/3 and 2/4 meet up instead of 1/4 and 2/3. No-one cares about that. It's about who meets who. And it;s strange that outside clay, Fed and Djoko met for 4 years running!

Tennis Anarok what planet are you on?

Whether the 3rd or 4th seed ends upo in the same section as the 1st seed is linked to the which one remains to be in the same section as the 2nd seed. That is one event per slam with the same odds as me tossing a coin and it landing heads or tails (OK there are claims that one side of the coin with its design is invariably slightly heavier than the other skewing the results to 50.00000 someting vs. 49.9999 someting - but that's another story.

Whether you believe I know much about tennis draws, coin tossing etc... I have a degree in biological sciences and spent two to three months laboriously anaysing chromosal aberrations with a plethora of statsitical methods and know an anomaly when I see one. Tennis related or not.

no one's answered one of my objections yet, which is that in the years considered Djokovic was arguably a bigger threat to Nadal on clay than on grass, yet these students chose to keep grass and throw away the clay.

Exactly, those were my points too newballs. Points that render the conspiracy irrelevant. The conspiracy theorists are simply looking at the output names when they should be looking at the SEEDS as those are what go into the draw!!!

Based on that you would normally have a distribution 50:50 for either 1v3, 2v4 or 1v4, 2v3. At the last 14 slams from 2011 backwards it was 6 and 8...nearly 50%. It just happened that Nole was moving around in the rankings. This situation is also exacerbated by the unusual fact that the top 4 has been the most stable top4 in the Open Era so it allows for more of these "name" quirks to arise.

Here's the raw data:

2008 Wimbledon
Seed 1: Roger Federer (Top half)
Seed 2: Rafael Nadal (Bottom half)
Seed 3: Novak Djokovic (Top half)
Seed 4: Nikolay Davydenko (Bottom half)
1/3 in top half, 2/4 in bottom half.

2008 US Open
Seed 1: Rafael Nadal (Top half)
Seed 2: Roger Federer (Bottom half)
Seed 3: Novak Djokovic (Bottom half)
Seed 4: David Ferrer (Top half)
1/4 in top half, 2/3 in bottom half.

2009 Australian Open
Seed 1: Rafael Nadal (Top half)
Seed 2: Roger Federer (Bottom half)
Seed 3: Novak Djokovic (Bottom half)
Seed 4: Andy Murray (Top half)
1/4 in top half, 2/3 in bottom half.

2009 French Open
Seed 1: Rafael Nadal (Top half)
Seed 2: Roger Federer (Bottom half)
Seed 3: Andy Murray (Top half)
Seed 4: Novak Djokovic (Bottom half)
1/3 in top half, 2/4 in bottom half.

2009 Wimbledon
Seed 1: Rafael Nadal (Top half - withdrew from tournament)
Seed 2: Roger Federer (Bottom half)
Seed 3: Andy Murray (Top half)
Seed 4: Novak Djokovic (Bottom half)
Seed 5: Juan Martin del Potro (Top half - replaced Nadal at the top of the draw)
1/3 in top half, 2/4 in bottom half.

2009 US Open
Seed 1: Roger Federer (Top half)
Seed 2: Andy Murray (Bottom half)
Seed 3: Rafael Nadal (Bottom half)
Seed 4: Novak Djokovic (Top half)
1/4 in top half, 2/43 in bottom half.


2010 Australian Open
Seed 1: Roger Federer (Top half)
Seed 2: Rafael Nadal (Bottom half)
Seed 3: Novak Djokovic (Top half)
Seed 4: Juan Martin del Potro (Bottom half)
1/3 in top half, 2/4 in bottom half.


2010 French Open
Seed 1: Roger Federer (Top half)
Seed 2: Rafael Nadal (Bottom half)
Seed 3: Novak Djokovic (Bottom half)
Seed 4: Andy Murray (Top half)
1/4 in top half, 2/3 in bottom half.

2010 Wimbledon
Seed 1: Roger Federer (Top half)
Seed 2: Rafael Nadal (Bottom half)
Seed 3: Novak Djokovic (Top half)
Seed 4: Andy Murray (Bottom half)
1/3 in top half, 2/34 in bottom half.


2010 US Open
Seed 1: Rafael Nadal (Top half)
Seed 2: Roger Federer (Bottom half)
Seed 3: Novak Djokovic (Bottom half)
Seed 4: Andy Murray (Top half)
1/4 in top half, 2/3 in bottom half.

2011 Australian Open
Seed 1: Rafael Nadal (Top half)
Seed 2: Roger Federer (Bottom half)
Seed 3: Novak Djokovic (Bottom half)
Seed 4: Robin Soderling (Top half)
1/4 in top half, 2/3 in bottom half.

2011 French Open
Seed 1: Rafael Nadal (Top half)
Seed 2: Novak Djokovic (Bottom half)
Seed 3: Roger Federer (Bottom half)
Seed 4: Andy Murray (Top half)
1/4 in top half, 2/3 in bottom half.

2011 Wimbledon
Seed 1: Rafael Nadal (Top half)
Seed 2: Novak Djokovic (Bottom half)
Seed 3: Roger Federer (Bottom half)
Seed 4: Andy Murray (Top half)
1/4 in top half, 2/3 in bottom half.

2011 US Open
Seed 1: Novak Djokovic (Top half)
Seed 2: Rafael Nadal (Bottom half)
Seed 3: Roger Federer (Top half)
Seed 4: Andy Murray (Bottom half)
1/3 in top half, 2/4 in bottom half.


So in these 14 majors from 2008 Wimbledon to 2011 US Open there were 6 occurrences of seeds 1&3 in the top half and seeds 2&4 in bottom half, and there's been 8 occurrences of seeds 1&4 in the top half and seeds 2&3 in the bottom half. Nearly 50:50! There is no conspiracy...only theorists with an agenda!

Yes, Newballs. I agree that in each slam, it is akin to tossing a coin. After that, your post peters out into your background instead pf going through with your argument. I am keen to hear yourr point of view.

newballs wrote:Whether you believe I know much about tennis draws, coin tossing etc... I have a degree in biological sciences and spent two to three months laboriously anaysing chromosal aberrations with a plethora of statsitical methods and know an anomaly when I see one. Tennis related or not.

Yes and GW Bush was president of the USA....even got re-elected.

Tenez I do a lot of thinking.

It appears there's a sizeable element on this forum who seem incapable of realising that the numbers on the balls I assume they use do not have Federer or Djokovic's or anybody else's name on them . THEY HAVE 3 AND 4- if that helps you at all.

I am going to lie down in a darkened room now and pretend this thread never actually happened.

oh and newballs is correct, a coint toss is in fact not 50/50, it's slightly biased towards tails as the "head" side is (usually) slightly heavier than the "tail" side. So really if you want to bet on the outcome of a series of 12 coin tosses your best bet would be TTTTTTTTTTTT

Also, would someone like to have a go at the following teaser?

Consider a TV show where the contestant has the chance to win a car. For this he has to choose one of three curtains the car could be behind. The presenter knows which one it is. The contestant makes his choice, the presenter then reveals one of the two other curtains - the one (we know there's at least one) behind which the car isn't. He then offers the contestant the chance to change his choice. What should the contestant do?

I have trawelled through this and this is the biggest load of hand shuffle I have seen.

The data is corrupt and therefore not can not be accepted.

I work in an area that deals with data and if I was given this crap, I would march the data collector to the nearest post to be shot!

legendkillarV2 wrote:I have trawelled through this and this is the biggest load of hand shuffle I have seen.

The data is corrupt and therefore not can not be accepted.

I work in an area that deals with data and if I was given this crap, I would march the data collector to the nearest post to be shot!

shooting is too kind for these people IMO, but the sentiment is appreciated

Tenez

What are your mathematical qualifications? If you could list the ones directly related to statistics and in particular probability in bold that would be helpful.

Doesnt stop the usual garbage though LK....

Mad for Chelsea wrote:Also, would someone like to have a go at the following teaser?

Consider a TV show where the contestant has the chance to win a car. For this he has to choose one of three curtains the car could be behind. The presenter knows which one it is. The contestant makes his choice, the presenter then reveals one of the two other curtains - the one (we know there's at least one) behind which the car isn't. He then offers the contestant the chance to change his choice. What should the contestant do?

I think change. There is only a 1 in 3 chance he got it right first time. This is quite tricky though. I could be wrong. I hope not because I have heard this before some years ago.

Henman Bill wrote:

Mad for Chelsea wrote:Also, would someone like to have a go at the following teaser?

Consider a TV show where the contestant has the chance to win a car. For this he has to choose one of three curtains the car could be behind. The presenter knows which one it is. The contestant makes his choice, the presenter then reveals one of the two other curtains - the one (we know there's at least one) behind which the car isn't. He then offers the contestant the chance to change his choice. What should the contestant do?

I think change. There is only a 1 in 3 chance he got it right first time. This is quite tricky though. I could be wrong. I hope not because I have heard this before some years ago.

you would be correct

I'd give you a car, but I don't have one

Lydian is abck with the same argument which is patently wrong.

Let me spell it out for you, Lydian.

It is not 6 and 8 occurrences, but a specific pattern of those. Consider only 4 tournaments for simplicity. If a 1-3 occurrence is a head and a 1-4 occurrence a tail, we are talking of something like HHTT. HTHT while having 2 heads and 2 tails is not enough.

It isn't the number of heads and tails that have to match, it is the specific sequence.

Once again, if Fed and Djoker were 1-3 for the first two slams and 1-4 for the second two slams, we would need two heads followed by two tails to make sure they meet in the semis. A head, tail, tail, head will not yield the pattern. There is a world of difference between specifying the number of heads in 12 tosses and specifying the exact order we need the heads and tails.

Think about it. A couple having 2 boys and 2 girls is far more likely than the first child being a boy, the second a girl, the third a girl and the fourth a boy.

Order matters, and you are completely ignoring it.

hawkeye wrote:Tenez

What are your mathematical qualifications? If you could list the ones directly related to statistics and in particular probability in bold that would be helpful.

Anyone who has done a scientific degree at University or was born with a rational logical brain should be able to pick a few holes in these studies. We don't need a stats prof here.

legendkillarV2 wrote:I have trawelled through this and this is the biggest load of hand shuffle I have seen.

The data is corrupt and therefore not can not be accepted.

I work in an area that deals with data and if I was given this crap, I would march the data collector to the nearest post to be shot!

legendkillar what makes it worse is the researcher comes from one of those states which fix every year's Eurovision Song Contest by voting for their neighbouring one regardless of whether they can sing or not!

If and when that trend stops and we stop getting nil pointsi'll take another look at her data.

Come on Engelbert. You can do it!!

Why not direct the anger at the players for holding the same ranking each year!!

These 4 seeds need to be tested at once for denying the mathimatical probabilities without using PED's!

hawkeye wrote:Tenez

What are your mathematical qualifications? If you could list the ones directly related to statistics and in particular probability in bold that would be helpful.

I can add, multiply, substract and even divide on a good day. Which I did not think was anything special...until I read this thread....then I realised I belonged to a priviledged small club.