Sir Graham Henry criticises England approach

[Darwin]

Using some pretty pictures I will illustrate that there is indeed a correlation between adult playing number and success at the top level (basically confirming what the likes of gingergenius have already stated):



This shows that as registered adult player numbers* increase, the IRB ranking points increase. For those who aren't statistically inclined, the r2 ​value basically represents the proportion of variation in the dependent variable (IRB Ranking points) that is explained by the independent variable (Registered adult player numbers). So a r2 ​value of 0.431 suggests that 43% of the variance in IRB Ranking points is determined by adult player numbers - the remaining 57% is controlled by other factors (Rugby structuring in the country, coaching etc). The fact the the best correlation is logrithmic (a curve that tapers off) rather than linear (a straight line) suggests that once you get past a certain number of playing numbers, adding more players players doesn't substantially affect your ranking points. If we look at the outlying data points on the graph we see that New Zealand and Australia are doing much better than would be expected if ranking points were purely determined by adult playing numbers, while Japan and USA are doing substantially worse (and everyone else in the top 20 isn't too far off what would be expected..).



Right, now I've probably gone and thoroughly confused everyone I'm going to go water-blast the house before the Sevens starts in a few hours



*taken from here - I have no idea of the accuracy or otherwise of these numbers....

 

[Feicarsinn]

Objection! R-squared values are only really applicable to linear graphs.


Anyways, excel is for suckas.

 

[Darwin]

Objection! R-squared values are only really applicable to linear graphs.


Anyways, excel is for suckas.

Shoosh.....I know that is generally the case, but no-one else does

You actually get a pretty good r-squared for a linear line in any case (around 0.3), so the point remains valid... I will try to be more accurate in future in-case someone with some knowledge of stats is around to pick me up on my errors It is also worth noting that a correlation does not necessarily suggest a causal relationship, but people don't need to know that either....

Excel is fine for us non-professional/semi-pro graph makers like myself; I'm sure pro's like yourself use much more sophisticated technology!

 

[Feicarsinn]

Shoosh.....I know that, but no-one else does

You actually get a pretty good r-squared for a linear line in any case (around 0.3, P<0.05), so the point remains valid... I will try to be more accurate in future in-case someone with some knowledge of stats is around to pick me up on my errors

Excel is fine for us non-professional graph makers like myself, I'm sure pro's like yourself use much more sophisticated technology!

Eh? Since when is 0.3 a good R-squared value? Doesn't matter anyway though, if you took the natural log of the ranking points and number of registered players you'd probably get a straight line, so there's obviously some proportionality.

/pedantry.

 

[Darwin]

Eh? Since when is 0.3 a good R-squared value? Doesn't matter anyway though, if you took the natural log of the ranking points and number of registered players you'd probably get a straight line, so there's obviously some proportionality.

/pedantry.

Anywhere that isn't a phyiscs/maths textbook! Depending on your degrees of freedom, and r-squared of 0.3 can be a great value (though not so much in this case..). Most 'pseudo-scientists' such as myself would be delighted to get an r-squared of 0.3, as the variation in the biological world is much greater than you will find in the field of physics (I frequently see r-squared values of around 0.1 touted as 'strong correlations!')

Anyways...

 

[racingmetrofan]

The point is not that England has however many hundreds of thousands (or a million) of players to choose from. Its the overall playing numbers that determine how many top echelon players you have the potential to end up with. Only a certain percentage will rise to the top, like cream in a container.

Lets say you have a pint of full cream milk, and 100 ml of cream rises to the top. If you have a gallon of the same full cream milk under the same conditions, you'll get 800 ml of cream rising to the top. The greater your player base (more milk), the more potential top echelon players (more cream) you should have. Its straight-out statistical probability. Same applies in any work place. If you have 25 staff, then your chances of you having enough people to put together half-decent rugby team are pretty slim, but if you have 5000 staff, then your chances of achieving this are dramatically increased; if you have 50,000 staff, you are likely to have the makings of a Provincial/Club team in there.

The numbers thing isn't really true, because you can only have a top 15 at the end of the day, a top 23 at most. Look at Dan Carter for instance ( a great example of a 'top flight' player). If you doubled NZs population, one might assume that you'd have another with the same intrinsic skillset. But you'd never have two players at the level of Dan Carter, because for Dan Carter to be Dan Carter he's got to start all those international matches, kick all those penalties, perform those winning runs etc. Two can't reach that height at the same time.

A better example (than the milk and cream) would be a special type of wine, that has to be matured in a special, exceptionally difficult place to replicate over a 5 year period (say in the one 200 year old barrel of particular oak the company has).

You can produce as many grapes as you want, but only one batch is going to be in the barrell for 5 years. Even if you put it in the next best barrel, it isn't going to be the same.

At the highest level, the more = more doesn't really apply. THe only thing I think one can infer from Englands exceptionally large playing numbers is that the selectors shoud have more choice of potential to develop...

 

[Seaton]

The numbers thing isn't really true, because you can only have a top 15 at the end of the day, a top 23 at most. Look at Dan Carter for instance ( a great example of a 'top flight' player). If you doubled NZs population, one might assume that you'd have another with the same intrinsic skillset. But you'd never have two players at the level of Dan Carter, because for Dan Carter to be Dan Carter he's got to start all those international matches, kick all those penalties, perform those winning runs etc. Two can't reach that height at the same time.

A better example (than the milk and cream) would be a special type of wine, that has to be matured in a special, exceptionally difficult place to replicate over a 5 year period (say in the one 200 year old barrel of particular oak the company has).

You can produce as many grapes as you want, but only one batch is going to be in the barrell for 5 years. Even if you put it in the next best barrel, it isn't going to be the same.

At the highest level, the more = more doesn't really apply. THe only thing I think one can infer from Englands exceptionally large playing numbers is that the selectors shoud have more choice of potential to develop...

The point is not only about having two Dan Carters playing for the 10 spot.

It is about having a 'Dan Carter' that can play at fly-half. Then another 'Dan Carter' who is primarily a prop, and another that is a wing, etc...

The numbers apply when players are getting to the highest level. School boy and age grade is where the bulk counts. The more youngsters playing, the more options there are to get invited to academies and such, so you are left with less dross than others when you get to the highest level of junior rugby. (and then senior/ pro)

 

[Peat]

I will pause for a moment before answering to imagine a Dan Carter that plays at prop.

A complete ball-playing, line-breaking prop with gas to burn.

Actually, I am not going to answer, I am just going to imagine the magic that would be Daniel Carter's skills, but in the body of a prop and taught to scrummage...

 

[big ginger 8]

Mike Ross is already the prop incarnation of Carter.

 

[Tomsey]

i think everyone is getting a bit carried away with henry's "more players = more success" comment. if you re-read the article you will notice that henry isn't using the stat to proclaim that england should be the best team in the world automatically because they have a bigger player pool. He brings it up to back up his comment that england are wasting their rugby talent due to poor management. all things being the same (culture, youth identification/nurture, etc. etc) the country with the biggest pool of players should be the better team. england don't have the right culture youth identification/nurture etc. so they aren't the best team (or perhaps more correctly aren't as good a team as they should be). comprende?

 

[Peat]

Already comprehended, already agreed with, already known by everyone.