Cybereagles

The Undisputed Number One Home for All Super Eagles Fans
It is currently Wed Nov 21, 2018 4:55 am

All times are UTC + 1 hour




Post new topic Reply to topic  [ 104 posts ]  Go to page Previous  1, 2, 3, 4, 5  Next
Author Message
PostPosted: Thu Aug 23, 2018 2:15 am 
Offline
User avatar

Joined: Mon Dec 06, 2004 2:39 am
Posts: 16644
Location: Super Eagles Homeland
Chief Ogbunigwe wrote:
metalalloy wrote:
Chief Ogbunigwe wrote:

You have helped me make my point. If we all agree that the MRI test is flawed, we can live with it being the best option ONLY on condition that the powers are not exploiting the flaws to cheat. That is my whole point. I have no issues going for the only feasible option if only we were confident that the selection and verification processes are conducted in GOOD FAITH.


Reports state that typically, complete fusion is unlikely to occur prior to 17 years of age, with an accuracy at greater than 99 percent.

https://www.thenational.ae/sport/use-of ... e-1.479733

If complete fusion is unlikely to occur before age 17, it makes sense to test for those players who haven't achieved complete fusion and rely on that fact that they are most likely under 17. Again, I go back to the point I made in the previous MRI thread, are you guys stating that Nigeria has an abundance of talented adults older than age 17, with a degree of fusion that is below Grade 6 sitting around that the NFF can tap into in order to make up a team? Whie i don't discount the possibility that that the NFF could be trying to include older players, and relying on a successful MRI test as cover, they would need to find a ton of these "needles in haystack" overaged individuals to make out a team of 23. The NFF only started conducting the MRI tests when the camp had been whittled down to 60 players, and could only afford to test 40 of them at the moment.


I hear what you are saying, but I disagree with the so-called 99% accuracy. As long as that number remains questionable, it's anyone's guess how many "overage" players have to be screened to get the desired number of candidates. Reputed academics disagree on the value/accuracy of the test. I actually challenged that study when it first came out even before I knew about the potential controversy it would generate among scientists in the field (we debated with Damunk, who even wrote the author to interrogate him :woot: :woot: :woot: ).

My current position is based on a combination of the highly likely inaccuracy of the test, and my personal suspicions that unscrupulous folks could be gaming the system. I remain very skeptical until further evidence supports this testing.


Chief,

Let me add a few things:

1. The study completed in 2006 has been validated by several other studies. In essence, its findings have been supported by subsequent academic work by others.

2. Controversy related to an academic study is not uncommon. In fact, is to be expected. Note that Copernicus' claim about the earth being spherical took years to accept and he was initially rejected by the church which was strong then (This is what paradigm shift in knowledge is all about - a struggle between thesis and anti-thesis)). Hegel claims that such struggle between an existing thesis of knowledge (the status quo) and an anti-thesis (new knowledge) is actually how change in learning occurs and naturally there is vigorous debate. Nothing new. Note the issue with head injuries and CTE in American football and the controversies and criticisms.

3. Note that the main article that criticized the use of MRI cited the fact that studies had not used Subsaharan samples. Guess what? Since then, there have been studies of footballers in Ghana and Senegal. The Senegal study (along with studies in Egypt and Algeria) affirm the findings but not the study in Ghana. But note that the Ghana study simply accepted a sample of Ghanaian youth footballers without a verification of their actual age and, thus, that may explain the results. I state this because the authors of that study acknowledge that sampling is a limitation on their study. In other cases, the age of the youths were verified. This verification is essential or else the correlations sought in the study cannot be effectively tested.

The point that I make here is that additional studies have taken place since 2006 to further affirm those findings. BTW, there are a host of studies using additional methods for estimating age of persons. MRI of the wrist is one of those studies and I can sendto you links to several of the studies that I mention here, at least the ones that I have access to.

_________________
The difficulties of statistical thinking describes a puzzling limitation of our mind: our excessive confidence in what we believe we know, and our apparent inability to acknowledge the full extent of our ignorance and the uncertainty of the world we live in. We are prone to overestimate how much we understand about the world and to underestimate the role of chance in events -- Daniel Kahneman (2011), Winner of the Nobel Prize in Economics
Winner of the Nobel Prize in Economics


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 2:40 am 
Offline
User avatar

Joined: Mon Dec 29, 2003 9:22 pm
Posts: 45040
Chief Ogbunigwe wrote:
Metal:

Lets look out this for a minute.... 15 of 40 failed. If the test TRULY has a 99% accuracy, that means approximately 37% of the candidates are overaged.... Isn't it alarming that close to 40% of candidates showed up with dodgy documents and claims? Again, if we believe the MRI, should we be concerned about the sheer number of folks willing to cheat, as well as their enablers? Unless we are saying that people who pass are 99% likely to be U-17, while those who failed may or may not be >17, but....too bad for them.






A large quantity of players 'failing" the MRI is concerning, but people will always be willing to cheat. Until a better test of verifying the age of the players is adopted, using the flawed MRI test is the best way to get rid of true or possible overaged players. Unfortunately, some truly underaged players may have to pay the price as they may be unfairly excluded because they developed faster than their peers.

E2 pointed out that several of those that "failed" had 5A and 5B fusion rates which is a "Pass" as those kids have not yet achieved complete fusion at the moment, however, their bones may be completely fused by the next round of testing, so the NFF is eliminating them now, to avoid dealing with that in a few months time. The true number of players with complete fusions (i.e. grade 6 and greater is reportedly seven players out of 40, (i.e. a 17% rate). In addition, some "failures" reportedly had to do with anomalies in their passports which might even reduce that failure rate. 17% is still too high.


The highlight is exactly what we are saying. This is why we maintain that the test is still not perfect as it captures/ eliminates some rare instances of players who are not <17 but have undergone complete fusion, and at the same time could include instances where an overaged player over the age of 17 hasn't undergone complete fusion.

Assuming the NFF is truly affirmatively stuffing the team with overaged players, i wonder what age leads to a true advantage over genuine 16 year olds. Is it ages 18? 19? mid 20's? I personally would love to see a study conducted on adults 20 years and older to see if there is any instance where someone has a fusion rate less than Grade 6.

_________________
We have been brainwashed by the Premier League that it's the best in the world. Nonsense. It's the best brand
Roy Keane: ITV 02/25/14

He says that we are currently "brainwashed" into believing that the Premier League is the best competition in the world, and that we are now a long way off dominating the Champions League again.
Gary Neville: Mirror: 12/23/14

I think Spain’s by far the best league.
Scholes. UK Guardian 9/6/16


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 8:06 am 
Offline
Moderator
User avatar

Joined: Tue Dec 23, 2003 5:57 pm
Posts: 37264
Location: UK
metalalloy wrote:
Chief Ogbunigwe wrote:
Metal:

Lets look out this for a minute.... 15 of 40 failed. If the test TRULY has a 99% accuracy, that means approximately 37% of the candidates are overaged.... Isn't it alarming that close to 40% of candidates showed up with dodgy documents and claims? Again, if we believe the MRI, should we be concerned about the sheer number of folks willing to cheat, as well as their enablers? Unless we are saying that people who pass are 99% likely to be U-17, while those who failed may or may not be >17, but....too bad for them.






A large quantity of players 'failing" the MRI is concerning, but people will always be willing to cheat. Until a better test of verifying the age of the players is adopted, using the flawed MRI test is the best way to get rid of true or possible overaged players. Unfortunately, some truly underaged players may have to pay the price as they may be unfairly excluded because they developed faster than their peers.

E2 pointed out that several of those that "failed" had 5A and 5B fusion rates which is a "Pass" as those kids have not yet achieved complete fusion at the moment, however, their bones may be completely fused by the next round of testing, so the NFF is eliminating them now, to avoid dealing with that in a few months time. The true number of players with complete fusions (i.e. grade 6 and greater is reportedly seven players out of 40, (i.e. a 17% rate). In addition, some "failures" reportedly had to do with anomalies in their passports which might even reduce that failure rate. 17% is still too high.


The highlight is exactly what we are saying. This is why we maintain that the test is still not perfect as it captures/ eliminates some rare instances of players who are not <17 but have undergone complete fusion, and at the same time could include instances where an overaged player over the age of 17 hasn't undergone complete fusion.

Assuming the NFF is truly affirmatively stuffing the team with overaged players, i wonder what age leads to a true advantage over genuine 16 year olds. Is it ages 18? 19? mid 20's? I personally would love to see a study conducted on adults 20 years and older to see if there is any instance where someone has a fusion rate less than Grade 6.
I am sure there must be such studies conducted strictly for clinical, non-footballing reasons.
Orthopedic journals is a starting point, but from all indications such a case would be quite rare and of clinical significance.

_________________
"Ole kuku ni gbogbo wọn "


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 11:22 am 
Offline
Moderator
User avatar

Joined: Fri Jan 02, 2004 9:16 am
Posts: 19787
Location: Canada
amafolas wrote:
felarey wrote:
Enugu II wrote:
felarey wrote:
Cellular wrote:
folem wrote:
15 out of 40 Nigeria U-17 players fail age test

Quote:
At least 15 out of 40 players of the Nigerian Under-17 squad chosen for the African Cup of Nations tournament (AFCON) qualifiers have failed a mandatory age test.

The Magnetic Resonance Imaging (MRI) tests revealed that some players were said to be much older than the required age limit.

Score Nigeria revealed that the 15 players have been expelled from the Golden Eaglets squad with another batch of 15 players set to undergo age tests before replacing the players who failed the age test.

Last year a similar incident occurred when as many as 23 players failed the age test that resulted in the Golden Eaglets failing to qualify for the 2017 Under-17 AFCON tournament in Rwanda.

The seven-team qualifying tournament taking place in September is to be held in Niger with only the tournament winners advancing to the AFCON tournament in Tanzania next year.

In 2016, Nigeria's 2015 FIFA Under-17 World Cup squad - who won the tournament for a record fifth time - had 26 of their 60 tested players disqualified after failing a mandatory MRI screening.

Only two of their starting XI remained available to play after the 26 players were deemed ineligible.

MRI scans can determine whether a player is below 17 with 99% accuracy.


We are just insincere people. My eye don open well well since moving back.

ZERO accountability. From a coach who still has his job after being caught on tape collecting a bribe to coaches and football officials who perpetrate this fraud.

TXJ is right. They choose players who are able to beat the test. Has nothing to do with their real age.

It's much worse, they choose players passed eligible by those interpreting the tests.



I guess they do that for CAF as well or how do they get past CAF?

In the past some have passed the Nigeria one and failed the CAF one. Players kicked out close to tournament start date.
I bet if we subject the 25 of 40 that passed to CAF, there will be failures and potentially there may be passes among the 15 failed. Elite footballers good enough to be considered for the national team tend to be well known household names in their communities and they play football outdoors where people see them. They are often used as mercenaries representing different teams and have a track record. Anyone that has lived the nigerian experience knows this. My senior in secondary school Sunday Ominu failed to get into Kanu's '93 set. His age wasn't in question.


Damunk has added a lot of good points to this discourse. I will add that gradings of levels of fusions are relatively subjective. I can get 5 independent radiologists and I am pretty sure there will be variance in their grading. Overall, their reads will correlate, but when you get to the borderline, it's not always so black and white. So yes people passing Naija MRI and failing CAF one later, might not just be down to deliberate intent to cheat or players getting older and having bones then fuse, there's also observer variability. The best thing Naija can do to mitigate that is to cut off guys who are boerderline.

Chief O, it would be nice for Nigeria to get their act together and actually have correct, verifiable birth certificates. Heck, NFF can conduct independent investigations to trace the background of every player as much as is feasible to narrow down their likely real age. But economically speaking, it's just cheaper to do an MRI, and weed out those are fused/ nearly fused. MRI test is very very flawed, but I think it's the most practical solution for a flawed environment like Naija. At worst, there's 95%+ probability that the MRI-passing players are at most a few years older than 18. Maybe someday in our lifetime, Nigeria will get its act together and no longer need such flawed solutions.

It's not cheaper to do an MRI, it's just more lucrative for those involved. That is why in 2018 they are assembling U17 kids that started junior high school in 2012 and resulting in 37.5% failure rate. If they do the right thing the failure rate cannot be that high. Assuming the test is any good.

_________________
"Winning one trophy is good, I tell you. No matter what trophy it might be, you've got to take it.” - Sir Alex Ferguson

ENGLISH PREMIERSHIP CHAMP20NS, UEFA CHAMPIONS LEAGUE WINN3RS


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 11:31 am 
Offline
Moderator
User avatar

Joined: Fri Jan 02, 2004 9:16 am
Posts: 19787
Location: Canada
Enugu II wrote:
Just to add:

I am beginning to think that people believe that the NFF has a CHOICE on this matter of using MRI.

Please note that this is a FIFA requirement for all those who belong to Confederations where birth documentation is deemed inaccurate or nonexistent. CAF is one such confederation. Thus, whether Nigeria wants it or not or whether Nigeria uses its own birth documents, they MUST still use the MRI test as a back up and their players will be further tested by CAF. Which means that a certain number will continue to fail the test.

The only way to avoid an MRI test in the current system is to provide a compelling argument that convinces FIFA that an MRI test is no longer required because Nigeria does and can affirm authenticity and accuracy of birth documentation of players that it presents.

Can we really be making the case that birth documentation is nonexistence in 2000-2002 when the oldest of these kids would have been born?? The MRI is FIFA's last chance at stemming a massive, existential plot to cheat. Nigeria has enough information to affirm the age of elite soccerstars born 2000-2002, it's only left for officials to do the right thing. We know what is going on here, lets not be too academic about this.

_________________
"Winning one trophy is good, I tell you. No matter what trophy it might be, you've got to take it.” - Sir Alex Ferguson

ENGLISH PREMIERSHIP CHAMP20NS, UEFA CHAMPIONS LEAGUE WINN3RS


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 11:33 am 
Offline
Moderator
User avatar

Joined: Fri Jan 02, 2004 9:16 am
Posts: 19787
Location: Canada
metalalloy wrote:
felarey wrote:
Enugu II wrote:
felarey wrote:
Cellular wrote:
folem wrote:
15 out of 40 Nigeria U-17 players fail age test

Quote:
At least 15 out of 40 players of the Nigerian Under-17 squad chosen for the African Cup of Nations tournament (AFCON) qualifiers have failed a mandatory age test.

The Magnetic Resonance Imaging (MRI) tests revealed that some players were said to be much older than the required age limit.

Score Nigeria revealed that the 15 players have been expelled from the Golden Eaglets squad with another batch of 15 players set to undergo age tests before replacing the players who failed the age test.

Last year a similar incident occurred when as many as 23 players failed the age test that resulted in the Golden Eaglets failing to qualify for the 2017 Under-17 AFCON tournament in Rwanda.

The seven-team qualifying tournament taking place in September is to be held in Niger with only the tournament winners advancing to the AFCON tournament in Tanzania next year.

In 2016, Nigeria's 2015 FIFA Under-17 World Cup squad - who won the tournament for a record fifth time - had 26 of their 60 tested players disqualified after failing a mandatory MRI screening.

Only two of their starting XI remained available to play after the 26 players were deemed ineligible.

MRI scans can determine whether a player is below 17 with 99% accuracy.


We are just insincere people. My eye don open well well since moving back.

ZERO accountability. From a coach who still has his job after being caught on tape collecting a bribe to coaches and football officials who perpetrate this fraud.

TXJ is right. They choose players who are able to beat the test. Has nothing to do with their real age.

It's much worse, they choose players passed eligible by those interpreting the tests.



I guess they do that for CAF as well or how do they get past CAF?

In the past some have passed the Nigeria one and failed the CAF one. Players kicked out close to tournament start date.
I bet if we subject the 25 of 40 that passed to CAF, there will be failures and potentially there may be passes among the 15 failed. Elite footballers good enough to be considered for the national team tend to be well known household names in their communities and they play football outdoors where people see them. They are often used as mercenaries representing different teams and have a track record. Anyone that has lived the nigerian experience knows this. My senior in secondary school Sunday Ominu failed to get into Kanu's '93 set. His age wasn't in question.


I cant imagine that anyone can pass after failing if the test is administered properly. Your bones are either fused or not, you cant go back and "unfuse" your bones.

That argument can be made both ways. We have cases of those that fail the CAF one after passing the Nigeria one. Still your bones are either fused or not.

_________________
"Winning one trophy is good, I tell you. No matter what trophy it might be, you've got to take it.” - Sir Alex Ferguson

ENGLISH PREMIERSHIP CHAMP20NS, UEFA CHAMPIONS LEAGUE WINN3RS


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 11:35 am 
Offline
Moderator
User avatar

Joined: Fri Jan 02, 2004 9:16 am
Posts: 19787
Location: Canada
Chief Ogbunigwe wrote:
Metal:

Lets look out this for a minute.... 15 of 40 failed. If the test TRULY has a 99% accuracy, that means approximately 37% of the candidates are overaged.... Isn't it alarming that close to 40% of candidates showed up with dodgy documents and claims? Again, if we believe the MRI, should we be concerned about the sheer number of folks willing to cheat, as well as their enablers? Unless we are saying that people who pass are 99% likely to be U-17, while those who failed may or may not be >17, but....too bad for them.

Exactly.

_________________
"Winning one trophy is good, I tell you. No matter what trophy it might be, you've got to take it.” - Sir Alex Ferguson

ENGLISH PREMIERSHIP CHAMP20NS, UEFA CHAMPIONS LEAGUE WINN3RS


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 2:53 pm 
Offline
User avatar

Joined: Mon Dec 29, 2003 9:22 pm
Posts: 45040
felarey wrote:

I cant imagine that anyone can pass after failing if the test is administered properly. Your bones are either fused or not, you cant go back and "unfuse" your bones.

That argument can be made both ways. We have cases of those that fail the CAF one after passing the Nigeria one. Still your bones are either fused or not.[/quote]

The argument can't be made the other way due to the timing of the tests. The Nigerian test is conducted earlier than the CAF test. The kids are still growing and fusion could occur during the time period between the tests. Hence, someone could pass the NIgerian test as they would not have undergone complete fusion at the time of the NIgerian test, and yet fail the CAF one because they had developed by the time of the later CAF test.

_________________
We have been brainwashed by the Premier League that it's the best in the world. Nonsense. It's the best brand
Roy Keane: ITV 02/25/14

He says that we are currently "brainwashed" into believing that the Premier League is the best competition in the world, and that we are now a long way off dominating the Champions League again.
Gary Neville: Mirror: 12/23/14

I think Spain’s by far the best league.
Scholes. UK Guardian 9/6/16


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 2:55 pm 
Offline
User avatar

Joined: Mon Dec 29, 2003 9:22 pm
Posts: 45040
felarey wrote:
Enugu II wrote:
Just to add:

I am beginning to think that people believe that the NFF has a CHOICE on this matter of using MRI.

Please note that this is a FIFA requirement for all those who belong to Confederations where birth documentation is deemed inaccurate or nonexistent. CAF is one such confederation. Thus, whether Nigeria wants it or not or whether Nigeria uses its own birth documents, they MUST still use the MRI test as a back up and their players will be further tested by CAF. Which means that a certain number will continue to fail the test.

The only way to avoid an MRI test in the current system is to provide a compelling argument that convinces FIFA that an MRI test is no longer required because Nigeria does and can affirm authenticity and accuracy of birth documentation of players that it presents.

Can we really be making the case that birth documentation is nonexistence in 2000-2002 when the oldest of these kids would have been born?? The MRI is FIFA's last chance at stemming a massive, existential plot to cheat. Nigeria has enough information to affirm the age of elite soccerstars born 2000-2002, it's only left for officials to do the right thing. We know what is going on here, lets not be too academic about this.



No one says that the birth documentation is nonexistent. See the highlighted.

_________________
We have been brainwashed by the Premier League that it's the best in the world. Nonsense. It's the best brand
Roy Keane: ITV 02/25/14

He says that we are currently "brainwashed" into believing that the Premier League is the best competition in the world, and that we are now a long way off dominating the Champions League again.
Gary Neville: Mirror: 12/23/14

I think Spain’s by far the best league.
Scholes. UK Guardian 9/6/16


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 3:41 pm 
Offline
Moderator
User avatar

Joined: Tue Dec 23, 2003 5:57 pm
Posts: 37264
Location: UK
felarey wrote:
That argument can be made both ways. We have cases of those that fail the CAF one after passing the Nigeria one. Still your bones are either fused or not.
:rotf: :rotf: :rotf: :rotf:
After all the explanations on bone growth, growth plate fusion etc and someone as intelligent as you can still be saying this, then it is no wonder this debate is never-ending and ultimately pointless.

Tell us your area of expertise and maybe someone can give you an appropriate analogy.

_________________
"Ole kuku ni gbogbo wọn "


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 3:45 pm 
Offline
User avatar

Joined: Mon Dec 06, 2004 2:39 am
Posts: 16644
Location: Super Eagles Homeland
Damunk wrote:
felarey wrote:
That argument can be made both ways. We have cases of those that fail the CAF one after passing the Nigeria one. Still your bones are either fused or not.
:rotf: :rotf: :rotf: :rotf:
After all the explanations on bone growth, growth plate fusion etc and someone as intelligent as you can still be saying this, then it is no wonder this debate is never-ending and ultimately pointless.

Tell us your area of expertise and maybe someone can give you an appropriate analogy.



:rotf: :rotf: Damunk,

Falarey na real wa! He thinks that people do not age every day and thus if your bone is unfused one day it must remain unfused forever. Thus, since Nigerian MRI showed Kelechi's wrist bone was unfused in 2015 it remains unfused today! LOL. Perhaps that extreme example shall help Falerey understand that because CAF's test comes months later after the Nigerian test that differences should naturally occur.

_________________
The difficulties of statistical thinking describes a puzzling limitation of our mind: our excessive confidence in what we believe we know, and our apparent inability to acknowledge the full extent of our ignorance and the uncertainty of the world we live in. We are prone to overestimate how much we understand about the world and to underestimate the role of chance in events -- Daniel Kahneman (2011), Winner of the Nobel Prize in Economics
Winner of the Nobel Prize in Economics


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 5:17 pm 
Offline

Joined: Fri Dec 26, 2003 7:55 pm
Posts: 8006
charlie wrote:
Cellular wrote:
TXJ is right. They choose players who are able to beat the test. Has nothing to do with their real age.



Wait a second, I am confused with your last statement. Are you saying that they know that MRI tests are not a viable test of a persons age, hence they just ignore the players actual age and focus on passing the test?

If so, makes me wonder if the people that created this MRI test were more interested in negating the physical advantage that Africans have at a certain age group.


The highlighted is obvious to every observer except the most naive of us. If you research the history of MRI testing by FIFA, you will discover that X-Rays were actually the preferred testing methodology. They offer a very high degree of accuracy but were discarded because of the dangers of radiation. MRI testing was hastily adopted in spite of its glaring shortcomings :!:


Cheers.


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 7:05 pm 
Offline

Joined: Mon Dec 29, 2003 3:25 pm
Posts: 6019
Brother Enugu II

You wrote the following:

Quote:
Note that the main article that criticized the use of MRI cited the fact that studies had not used Subsaharan samples. Guess what? Since then, there have been studies of footballers in Ghana and Senegal. The Senegal study (along with studies in Egypt and Algeria) affirm the findings but not the study in Ghana.


I have been scouring the internet, trying to find the details and results of the Senegalese test study, but to no avail.
Can you please share a link to the complete study and its findings?

This is what I found, another article written by Jiri Dvorak in 2009 in which he says:

Quote:
In 2003, in response to numerous requests by member associations, FIFA’s Medical Assessment and Research Centre (FMARC) started to investigate the use of biological markers for age determination. MRI scans of the wrist were performed in more than 500 football players who had confirmed birth certificates. These players of different ethnical origin (Switzerland, Malaysia, Algeria, Argentina, Senegal)


https://pdfs.semanticscholar.org/2cc5/d ... c7d05c.pdf

This immediately picked my interest because in the initial study in 2003, based on Jiri Dvorak's own statements, only 4 countries where included in the sample set used to develop the MRI rating system: Switzerland, Malaysia, Algeria and Argentina.

Quote:
In a previous study,8 496 healthy male adolescent soccer players between the ages of 14 and 19 from Switzerland, Malaysia, Algeria, and Argentina had an MRI examination of the left wrist, and a newly developed grading system was applied to determine the degree of epiphyseal fusion of the radius.


https://www.ncbi.nlm.nih.gov/pubmed/17021001/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2465442/

Questions:

1. When was Senegal added to the dataset used to develop the Dvorak grading system?
2. Was the Senegalese test you are referring to a test to validate the Dvorak grading system developed off the 2003 data, or was it used to enhance/re-calibrate the grading system?

I hope that by providing a link to the Senegalese test you are referring to, that might clarify the questions above.

_________________
Kola nut lasts long for those that savor it


Top
 Profile  
 
PostPosted: Thu Aug 23, 2018 8:33 pm 
Offline
User avatar

Joined: Mon Dec 29, 2003 9:22 pm
Posts: 45040
charlie wrote:
Brother Enugu II

You wrote the following:

Quote:
Note that the main article that criticized the use of MRI cited the fact that studies had not used Subsaharan samples. Guess what? Since then, there have been studies of footballers in Ghana and Senegal. The Senegal study (along with studies in Egypt and Algeria) affirm the findings but not the study in Ghana.


I have been scouring the internet, trying to find the details and results of the Senegalese test study, but to no avail.
Can you please share a link to the complete study and its findings?

This is what I found, another article written by Jiri Dvorak in 2009 in which he says:

Quote:
In 2003, in response to numerous requests by member associations, FIFA’s Medical Assessment and Research Centre (FMARC) started to investigate the use of biological markers for age determination. MRI scans of the wrist were performed in more than 500 football players who had confirmed birth certificates. These players of different ethnical origin (Switzerland, Malaysia, Algeria, Argentina, Senegal)


https://pdfs.semanticscholar.org/2cc5/d ... c7d05c.pdf

This immediately picked my interest because in the initial study in 2003, based on Jiri Dvorak's own statements, only 4 countries where included in the sample set used to develop the MRI rating system: Switzerland, Malaysia, Algeria and Argentina.

Quote:
In a previous study,8 496 healthy male adolescent soccer players between the ages of 14 and 19 from Switzerland, Malaysia, Algeria, and Argentina had an MRI examination of the left wrist, and a newly developed grading system was applied to determine the degree of epiphyseal fusion of the radius.


https://www.ncbi.nlm.nih.gov/pubmed/17021001/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2465442/

Questions:

1. When was Senegal added to the dataset used to develop the Dvorak grading system?
2. Was the Senegalese test you are referring to a test to validate the Dvorak grading system developed off the 2003 data, or was it used to enhance/re-calibrate the grading system?

I hope that by providing a link to the Senegalese test you are referring to, that might clarify the questions above.



Hmm this is a very good question. The original test most certainly didn't not include data with Senegal, and only tested 496 players. However, from 2009, when Dvorak and other articles talked about that test, they included Senegal as one of the test countries, and made reference to a test of more than 500 soccer players. e be like sey Dvorak don dey smoke igbo.

_________________
We have been brainwashed by the Premier League that it's the best in the world. Nonsense. It's the best brand
Roy Keane: ITV 02/25/14

He says that we are currently "brainwashed" into believing that the Premier League is the best competition in the world, and that we are now a long way off dominating the Champions League again.
Gary Neville: Mirror: 12/23/14

I think Spain’s by far the best league.
Scholes. UK Guardian 9/6/16


Top
 Profile  
 
PostPosted: Fri Aug 24, 2018 3:01 am 
Offline
Moderator
User avatar

Joined: Fri Jan 02, 2004 9:16 am
Posts: 19787
Location: Canada
Damunk wrote:
felarey wrote:
That argument can be made both ways. We have cases of those that fail the CAF one after passing the Nigeria one. Still your bones are either fused or not.
:rotf: :rotf: :rotf: :rotf:
After all the explanations on bone growth, growth plate fusion etc and someone as intelligent as you can still be saying this, then it is no wonder this debate is never-ending and ultimately pointless.

Tell us your area of expertise and maybe someone can give you an appropriate analogy.

I guess CAF waits long enough to perform their tests. Enough to waste the NFF and kids time preparing for competition. You guys say the test is not black n white, not infallible and conclusions can be subjective contradicting fused or not fused which is a boolean analogy. Continue to discuss the merits of a so called good test that brings about 37% failure rate on good people. The rest of us know exactly what is going on.

_________________
"Winning one trophy is good, I tell you. No matter what trophy it might be, you've got to take it.” - Sir Alex Ferguson

ENGLISH PREMIERSHIP CHAMP20NS, UEFA CHAMPIONS LEAGUE WINN3RS


Top
 Profile  
 
PostPosted: Fri Aug 24, 2018 4:31 am 
Offline
User avatar

Joined: Mon Dec 06, 2004 2:39 am
Posts: 16644
Location: Super Eagles Homeland
Charlie,

The questions are critical. I provide my answers based on my interpretations of the studies (see red highlights below).

metalalloy wrote:
charlie wrote:
Brother Enugu II

You wrote the following:

Quote:
Note that the main article that criticized the use of MRI cited the fact that studies had not used Subsaharan samples. Guess what? Since then, there have been studies of footballers in Ghana and Senegal. The Senegal study (along with studies in Egypt and Algeria) affirm the findings but not the study in Ghana.


I have been scouring the internet, trying to find the details and results of the Senegalese test study, but to no avail.
Can you please share a link to the complete study and its findings?

This is what I found, another article written by Jiri Dvorak in 2009 in which he says:

Quote:
In 2003, in response to numerous requests by member associations, FIFA’s Medical Assessment and Research Centre (FMARC) started to investigate the use of biological markers for age determination. MRI scans of the wrist were performed in more than 500 football players who had confirmed birth certificates. These players of different ethnical origin (Switzerland, Malaysia, Algeria, Argentina, Senegal)


https://pdfs.semanticscholar.org/2cc5/d ... c7d05c.pdf

This immediately picked my interest because in the initial study in 2003, based on Jiri Dvorak's own statements, only 4 countries where included in the sample set used to develop the MRI rating system: Switzerland, Malaysia, Algeria and Argentina.

Quote:
In a previous study,8 496 healthy male adolescent soccer players between the ages of 14 and 19 from Switzerland, Malaysia, Algeria, and Argentina had an MRI examination of the left wrist, and a newly developed grading system was applied to determine the degree of epiphyseal fusion of the radius.


https://www.ncbi.nlm.nih.gov/pubmed/17021001/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2465442/

Questions:

1. When was Senegal added to the dataset used to develop the Dvorak grading system?

I believe Senegal was part of the initial studies although I can understand some of the confusion as Senegal is not listed in some of the initial reports. However, I believe Senegal Switzerland, Algeria, Malaysia, and Argentina were the five countries where 496 footballers were sampled https://www.fifa.com/development/news/y=2009/m=10/news=caught-the-wrists-1121679.html. What I do not know is why sometimes Senegal is left out of the report. Note also that they had atlas two other studies. One involving another 189 players and another that included Tanzania on female footballers. The latter did not support use of MRI for females as the wrist bones fused much earlier in age.

2. Was the Senegalese test you are referring to a test to validate the Dvorak grading system developed off the 2003 data, or was it used to enhance/re-calibrate the grading system?As I mention above, it was part of the initial study used in developing the grading system. That is my belief but I am uncertain of that as I have found places where Senegal is referred to in the later study of 189 players.

Note that several studies have come afterwards pertaining to the same measure or comparing it to other measures. Two have been on African countries. The Egyptian study by Abdelbary et. al. support Dvorak's findings https://www.sciencedirect.com/science/article/pii/S0378603X1730219X. However, Sarkodie et.al. study of Ghanaian footballers does not but acknowledges issues with sample selected https://www.sciencedirect.com/science/article/pii/S2212478017300151
I hope that by providing a link to the Senegalese test you are referring to, that might clarify the questions above.



Hmm this is a very good question. The original test most certainly didn't not include data with Senegal, and only tested 496 players. However, from 2009, when Dvorak and other articles talked about that test, they included Senegal as one of the test countries, and made reference to a test of more than 500 soccer players. e be like sey Dvorak don dey smoke igbo.

_________________
The difficulties of statistical thinking describes a puzzling limitation of our mind: our excessive confidence in what we believe we know, and our apparent inability to acknowledge the full extent of our ignorance and the uncertainty of the world we live in. We are prone to overestimate how much we understand about the world and to underestimate the role of chance in events -- Daniel Kahneman (2011), Winner of the Nobel Prize in Economics
Winner of the Nobel Prize in Economics


Top
 Profile  
 
PostPosted: Fri Aug 24, 2018 4:37 am 
Offline
User avatar

Joined: Mon Dec 06, 2004 2:39 am
Posts: 16644
Location: Super Eagles Homeland
felarey wrote:
Damunk wrote:
felarey wrote:
That argument can be made both ways. We have cases of those that fail the CAF one after passing the Nigeria one. Still your bones are either fused or not.
:rotf: :rotf: :rotf: :rotf:
After all the explanations on bone growth, growth plate fusion etc and someone as intelligent as you can still be saying this, then it is no wonder this debate is never-ending and ultimately pointless.

Tell us your area of expertise and maybe someone can give you an appropriate analogy.

I guess CAF waits long enough to perform their tests. Enough to waste the NFF and kids time preparing for competition. You guys say the test is not black n white, not infallible and conclusions can be subjective contradicting fused or not fused which is a boolean analogy. Continue to discuss the merits of a so called good test that brings about 37% failure rate on good people. The rest of us know exactly what is going on.


Falerey,

I hope you realize that FIFA even waits longer. By the time the U17 competition starts, you do realize that several players in that competition are actually over 17 years of age based on eligibility DOB deadline. This affects all participants in the competition, whether in Africa, Europe or in the Americas. In essence, the FIFA competition is actually a U18!

_________________
The difficulties of statistical thinking describes a puzzling limitation of our mind: our excessive confidence in what we believe we know, and our apparent inability to acknowledge the full extent of our ignorance and the uncertainty of the world we live in. We are prone to overestimate how much we understand about the world and to underestimate the role of chance in events -- Daniel Kahneman (2011), Winner of the Nobel Prize in Economics
Winner of the Nobel Prize in Economics


Top
 Profile  
 
PostPosted: Fri Aug 24, 2018 5:33 pm 
Offline

Joined: Mon Dec 29, 2003 3:25 pm
Posts: 6019
Enugu II,

I have read and re-read the links you shared, and I have still found no proof that Senegal was ever part of the original Dvorak sample data, and in fact, I can prove definitively that Senegal was never part of the original data:

Here is a detailed report of the Dvorak MRI Age determination by MRI study published online in 2006:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2465138/

Please pay attention to Table 2 where it shows the exact break down of adolescents by country:
https://www.ncbi.nlm.nih.gov/pmc/articl ... objectonly

No Senegal. They were not part of the original 496 adolescents clearly.

Now, I am not saying the Dvorak grading system has not been recalibrated since the original test with Senegalese data. I am just saying that I have yet to see any definitive report explaining exactly when and how Senegalese adolescents participated in such an exercise, at least to the level of detail that we have seen in the links I have shared above.

Yet, at some point (at least from 2009 onwards), Dvorak and FIFA started adding Senegal as one of the countries in their original sample size (which we now know for certain was not the case). So it begs the perfectly valid to question of when Senegalese adolecents were tested and used to calibrate the Dvorak MRI scaling system.

I will keep looking for any study showing in detail the Senegalese MRI test and share what I have as soon as I find anything.

_________________
Kola nut lasts long for those that savor it


Top
 Profile  
 
PostPosted: Fri Aug 24, 2018 7:25 pm 
Offline
User avatar

Joined: Mon Dec 06, 2004 2:39 am
Posts: 16644
Location: Super Eagles Homeland
charlie,

But is it not inconceivable that you can simply add sample without ever using it. That is fraudulent, as you may know and I doubt that Dvorak can get away with it. My belief is that they did use Senegal, otherwise why would they mention Senegal? What is possible, is that they may have parsed the data in order to produce multiple reports, which is not unusual in research studies. I doubt that you will find a report from then based only on a Senegalese sample but if you do please share. What I think they have done is to use the samples integratively in several of their reports.

charlie wrote:
Enugu II,

I have read and re-read the links you shared, and I have still found no proof that Senegal was ever part of the original Dvorak sample data, and in fact, I can prove definitively that Senegal was never part of the original data:

Here is a detailed report of the Dvorak MRI Age determination by MRI study published online in 2006:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2465138/

Please pay attention to Table 2 where it shows the exact break down of adolescents by country:
https://www.ncbi.nlm.nih.gov/pmc/articl ... objectonly

No Senegal. They were not part of the original 496 adolescents clearly.

Now, I am not saying the Dvorak grading system has not been recalibrated since the original test with Senegalese data. I am just saying that I have yet to see any definitive report explaining exactly when and how Senegalese adolescents participated in such an exercise, at least to the level of detail that we have seen in the links I have shared above.

Yet, at some point (at least from 2009 onwards), Dvorak and FIFA started adding Senegal as one of the countries in their original sample size (which we now know for certain was not the case). So it begs the perfectly valid to question of when Senegalese adolecents were tested and used to calibrate the Dvorak MRI scaling system.

I will keep looking for any study showing in detail the Senegalese MRI test and share what I have as soon as I find anything.

_________________
The difficulties of statistical thinking describes a puzzling limitation of our mind: our excessive confidence in what we believe we know, and our apparent inability to acknowledge the full extent of our ignorance and the uncertainty of the world we live in. We are prone to overestimate how much we understand about the world and to underestimate the role of chance in events -- Daniel Kahneman (2011), Winner of the Nobel Prize in Economics
Winner of the Nobel Prize in Economics


Top
 Profile  
 
PostPosted: Fri Aug 24, 2018 9:45 pm 
Offline
User avatar

Joined: Fri Dec 26, 2003 2:35 pm
Posts: 36615
Location: Somewhere
Charlie, good questions. I no get time revisit my original critique of the original study, and I had taken EII's words for it that there was a subsequent study....

_________________
Image
AFCON 2015 sweet o
Barren for 35 yrs no good o

New member and Titled Chief, Distant Gunners Consortium.
"This is an island surrounded by water, big water, ocean water."


Top
 Profile  
 
PostPosted: Fri Aug 24, 2018 11:40 pm 
Offline
User avatar

Joined: Mon Dec 06, 2004 2:39 am
Posts: 16644
Location: Super Eagles Homeland
Chief Ogbunigwe wrote:
Charlie, good questions. I no get time revisit my original critique of the original study, and I had taken EII's words for it that there was a subsequent study....


Chief,

There were, indeed, subsequent studies not just by Dvorak's group but by others. I think that part of the critique from the study posted earlier by Txj have been somewhat addressed. The exception, however, is that one of those subsequent studies (one by Sarkodie) does not support the findings of Dvorak and his colleagues.The question unanswered, however, is at what point was Senegal studied.

_________________
The difficulties of statistical thinking describes a puzzling limitation of our mind: our excessive confidence in what we believe we know, and our apparent inability to acknowledge the full extent of our ignorance and the uncertainty of the world we live in. We are prone to overestimate how much we understand about the world and to underestimate the role of chance in events -- Daniel Kahneman (2011), Winner of the Nobel Prize in Economics
Winner of the Nobel Prize in Economics


Last edited by Enugu II on Fri Aug 24, 2018 11:58 pm, edited 1 time in total.

Top
 Profile  
 
PostPosted: Fri Aug 24, 2018 11:56 pm 
Offline
Moderator
User avatar

Joined: Fri Jan 02, 2004 9:16 am
Posts: 19787
Location: Canada
Enugu II wrote:
felarey wrote:
Damunk wrote:
felarey wrote:
That argument can be made both ways. We have cases of those that fail the CAF one after passing the Nigeria one. Still your bones are either fused or not.
:rotf: :rotf: :rotf: :rotf:
After all the explanations on bone growth, growth plate fusion etc and someone as intelligent as you can still be saying this, then it is no wonder this debate is never-ending and ultimately pointless.

Tell us your area of expertise and maybe someone can give you an appropriate analogy.

I guess CAF waits long enough to perform their tests. Enough to waste the NFF and kids time preparing for competition. You guys say the test is not black n white, not infallible and conclusions can be subjective contradicting fused or not fused which is a boolean analogy. Continue to discuss the merits of a so called good test that brings about 37% failure rate on good people. The rest of us know exactly what is going on.


Falerey,

I hope you realize that FIFA even waits longer. By the time the U17 competition starts, you do realize that several players in that competition are actually over 17 years of age based on eligibility DOB deadline. This affects all participants in the competition, whether in Africa, Europe or in the Americas. In essence, the FIFA competition is actually a U18!

They may be over 17 but they are not 18 which the MRI is supposed to eliminate. FIFA says a player in the U17 must be 17 at the end of the year the competition is played. For 2019, you must be born on or after January 2002. All tests take place when the players are meant to be 17 yrs old or less. 2 yrs ago we posted almost 50% failure rate in a qualifier in Niger that wiped out our first team. There is no such conspiracy where CAF and FIFA are sabotaging us targeting players that are now 18 yrs old.

_________________
"Winning one trophy is good, I tell you. No matter what trophy it might be, you've got to take it.” - Sir Alex Ferguson

ENGLISH PREMIERSHIP CHAMP20NS, UEFA CHAMPIONS LEAGUE WINN3RS


Top
 Profile  
 
PostPosted: Sat Aug 25, 2018 12:05 am 
Offline
User avatar

Joined: Mon Dec 06, 2004 2:39 am
Posts: 16644
Location: Super Eagles Homeland
felarey wrote:
Enugu II wrote:
felarey wrote:
Damunk wrote:
felarey wrote:
That argument can be made both ways. We have cases of those that fail the CAF one after passing the Nigeria one. Still your bones are either fused or not.
:rotf: :rotf: :rotf: :rotf:
After all the explanations on bone growth, growth plate fusion etc and someone as intelligent as you can still be saying this, then it is no wonder this debate is never-ending and ultimately pointless.

Tell us your area of expertise and maybe someone can give you an appropriate analogy.

I guess CAF waits long enough to perform their tests. Enough to waste the NFF and kids time preparing for competition. You guys say the test is not black n white, not infallible and conclusions can be subjective contradicting fused or not fused which is a boolean analogy. Continue to discuss the merits of a so called good test that brings about 37% failure rate on good people. The rest of us know exactly what is going on.


Falerey,

I hope you realize that FIFA even waits longer. By the time the U17 competition starts, you do realize that several players in that competition are actually over 17 years of age based on eligibility DOB deadline. This affects all participants in the competition, whether in Africa, Europe or in the Americas. In essence, the FIFA competition is actually a U18!

They may be over 17 but they are not 18 which the MRI is supposed to eliminate. FIFA says a player in the U17 must be 17 at the end of the year the competition is played. For 2019, you must be born on or after January 2002. All tests take place when the players are meant to be 17 yrs old or less. 2 yrs ago we posted almost 50% failure rate in a qualifier in Niger that wiped out our first team. There is no such conspiracy where CAF and FIFA are sabotaging us targeting players 18 yrs old.


Falerey,

Where did conspiracy enter into the conversation may I ask? The point is that by the time FIFA test is carried out, several players are already past the age of 17 and this is not particular to Nigeria but an issue that increases the chance of a number of the players having the wrist bone fused already (in theory at the least). But even at 17 years or under, players can and do fail the test even when they are actually age eligible. I hope that is understood, at the very least. TBH, I fee like a broken record, to have to repeat this reality.

_________________
The difficulties of statistical thinking describes a puzzling limitation of our mind: our excessive confidence in what we believe we know, and our apparent inability to acknowledge the full extent of our ignorance and the uncertainty of the world we live in. We are prone to overestimate how much we understand about the world and to underestimate the role of chance in events -- Daniel Kahneman (2011), Winner of the Nobel Prize in Economics
Winner of the Nobel Prize in Economics


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 104 posts ]  Go to page Previous  1, 2, 3, 4, 5  Next

All times are UTC + 1 hour


Who is online

Users browsing this forum: Google [Bot], vancity eagle and 35 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group