Analysis 2015 List Analysis and Comparison

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Unless I have completely forgotten my mathematics, with an AFL "average height" for each club, doesn't that mean that up to half the lists are either at, or below that mark, not just us ?
 
Thanks for the input - always happy to get some constructive criticism. :thumbsu:

I'm using IBM SPSS at the moment to generate the descriptives and the box plots (it also does histograms but I've been quickly re-doing them in Excel as it gives a little more flexibility with how it's presented), as well as some inferential statistics in other analyses. It's inputting the data that's time consuming. I'm definitely interested in looking at what else is out there to make this process a bit easier but for the moment SPSS is a booklisted program for my university course so it comes with the added bonus of extra practice.

List management/analysis and football stats analysis is something I have a keen interest in and have considered as a career path, but for the moment it's just a hobby more than anything else.



I agree; not a great point to make. What I was trying to say is that our height distribution (especially within the 181-195 range in particular) is much more positively skewed than those of the comparison teams'; we're "behind" in that our players are built up at a shorter height than the shown competitors' players. The use of the word "behind" wasn't intended to infer ladder position or quality or anything of the sort.


Thanks for going through with it and I appreciate all the work you've done. I can understand how this is time consuming for you because it seems like you are reviewing the data yourself. You need a data cube to make it faster to develop these visual aids.

Here is an example concerning Australian higher education: http://highereducationstatistics.education.gov.au/

I can come up with quantitative comparative analyses across universities (i.e. in terms of domestic/international students, casual staff/non casual, gender distributions etc.), similar to what you have done here with footy teams, but it takes **** all time because the software does it for me. When you have this kind of quick route it makes it easier to get to communicating and simplifying the importance of the results (which, if you dont mind a bit of constructive criticism, you seem to be good at but still have the capacity to further develop your skills).

Given the interest in footy, it'd be good for you to look in to the software for this (you seem to have a career interest in this area, if I am not mistaken).

Ever thought about an academic career in this area? looks to be fertile ground with plenty of interest...

WOW, you guys....
Gangsta, sounds like we are in the same industry, and also field of work. And Dannnnnn i expertise in IBM software that fits perfectly with SPSS. I thought I was the only one who had ideas like this. You can do so much with AFL stats, SPSS and TM1. Its a distant dream of mine to do something with all this. You do know that SPSS full version is predictive analytics right. If we combine our powers we could take over the AFL stats world lol.

Cube/dimension data is the way to go for stats
 
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Our 2015 list is the youngest in the AFL besides GC & GWS, and we are very close to them now. We didn't lose height on our main list this season, but we definitely lost age & experience. Not everyone on the list will grow, but players like Dale, Cordy, McLean & Hamilton could be 3cm taller in 3 years
I agree we didn't lose height from last year but I suspect we were already on the short side so comparing this season's list to the 2014 list is not a good reference point. I'd be quite surprised (and very pleased) if those four all grew 3 cm in 3 years.

Here's how much our 2011 draftees have grown in three years to now:
  • Clay Smith 180 --> 181 = 1 cm growth
  • Daniel Pearce 181 --> 181 = no change
  • Michael Talia 195 --> 194 = 1 cm "shrinkage"!
  • Tory Dickson 183 --> 184 = 1 cm growth (after age 24!)
These are all taken from the figures published on the WB website or the AFL Record Season Guide. I'm not seriously suggesting Talia has shrunk. There can easily be measuring discrepancies from year to year of up to a cm.

However the key thing is that growth of 3 cm in 3 years is rarely seen in even one player let alone an entire batch of draftees (I can provide more examples if you like). The last one I can find is Christian Howard who grew from 184 to 187 cm. Libba has grown 2 cm since he was drafted. My guess is that average growth from time of drafting (an 18yo) to the time they stop growing would be about 1 cm.

We haven't seen the average height for each side, only an overall AFL average. It would be interesting to see whether there is a correlation between average height and finishing position. I agree - it would be interesting. I do note that Hawthorn are below the AFL average despite winning the flag.

But what there is an undisputed correlation between is average age and finishing position. GC, GWS & us are at the bottom, whilst Hawthorn, Fremantle & North are at the top. Correct - nobody is disputing this. That's probably why not many rate us much of a chance in 2015.

Yet there hasn't been any discussion praising the club for going with Boyd, Biggs & Hamling as mature agers, as opposed to picking up more 18 year olds. There has been a little bit of discussion on it over the last month - but that discussion is more about maturity, experience and the relative merits of picking up other clubs' delisted players, not about height. (BTW, I'd be hesitant to call Tom Boyd a "mature ager" - he's only 5 months older than Toby McLean.) There has even been negative feedback from our retention of Goodes on the rookie list, to retain some experience after losing so much of it this off season

Not sure if we can even get a list of players on our list in 2011 for that. I have found the list - see below for results.

Calling it an imbalance is presuming we are too short. It is a fact that we are shorter than the AFL average, it is not established that the AFL average is the ideal list height. I agree there can be no certainty around this, only weight of opinion (and even weight of opinion doesn't necessarily make it right!) In the evolution of AFL match tactics and list strategies, clubs will always be trying to gain an edge in one area or another. Who's to say that taller is, of itself, better? Let's just say we look like being close to the shortest list in the AFL (tbc).
See various comments above in red. That we look like having one of the shortest (in stature) playing lists in the AFL seems likely. Where the discussion needs to go is whether this is a good thing, a bad thing or just inconsequential.

As for the 2011 v 2015 average heights, I have located the 2011 playing list (incl 6 rookies). Here's the interesting comparison:

2011 - average height 187.78 cm
2015 - average height 187.05 cm (I used heights listed on the WB website - Dannnn calculated an average of 186.82cm from a different source).

Furthermore I would guess that the average height across the AFL has risen by about 0.5 cm since then, in line with ongoing increases in the general population's average height. If correct, that would exacerbate the -0.73 cm difference between 2011 and 2015 (or -0.96 cm using Dannn's average).

You will probably be interested in an age comparison as well, so here goes:
2011 list - average age as at 20 Dec 2010 was 23.45
2015 list - average age as at 20 Dec 2014 is 22.95 - as expected, quite a bit younger.
 

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Not the point, we we've been too small for years and lack elite AFL quality in the minimal ones we have. Balancing our heights from last seasons should have been a minimum requirement not a pat on the back.

BUT seeing as though we're now going down a rebuilding phase properly and are one of the youngest teams in the AFL I think we can afford to get the best talent in and then work on getting the heights and shapes of the list sorted out in the next few trade periods.
You seem to have been consistently a couple of years behind the play on this one Butane. We're now consolidating because we now have the cattle with the possible exception of a quality KPD and half back. 2, possibly 3 players doesn't constitute a rebuild. The sensationally successful recruiting matrix that Macca introduced to the club has netted us quality players and leaders like Stringer, Macrae, Hrovat, Bontempelli, Jong etc etc. And treachery and circumstance have netted us a no.1 draft pick KPF (every cloud...).
Beveridge must be ecstatic at the highend quality of the list he's inherited and will no doubt be intent on getting match time/experience into this block of mainly 3rd, 4th and 5th year quality players (Bonts and T Boyd being 2nd year) so that next year when the block is mainly 4th, 5th and 6th year players we'll be ready for a 2013 Port style launch at finals in 2016. And like Port at the end of 2012 and in subsequent years since, a couple of astute off season acquisitions at the end of the year to plug the few gaps that remain.
 
Unless I have completely forgotten my mathematics, with an AFL "average height" for each club, doesn't that mean that up to half the lists are either at, or below that mark, not just us ?
You might be thinking of median (the mid-point in a series of numbers).
It can also be true of an average but it relies on having a fairly even and equal distribution above and below the average. I don't know what the distribution is like in this case.
 
Michael Talia 195 --> 194 = 1 cm "shrinkage"!

192cm when drafted

http://strategicma.com.au/michael-talia/
http://www.woof.net.au/forum/archive/index.php/t-10168.html
http://afltables.com/afl/stats/players/M/Michael_Talia.html
www.heraldsun.com.au/sport/afl/western-bulldogs-steal-a-bargain-in-afl-national-draft-with-michael-talia/story-fn53klc6-1226206209445

195cm now

http://www.footywire.com/afl/footy/pu-western-bulldogs--michael-talia
http://footybets.com/players/player/Michael+Talia/17061
http://www.*************.au/afl-players/michael-talia/

My guess is that average growth from time of drafting (an 18yo) to the time they stop growing would be about 1 cm.

It would be more than that for talls.

Height is most important for rucks, KPD's & KPF's. Our rucks are fine - Cordy 204, Campbell 201, Minson 199. Roughead 200, Talia 195 & Roberts 196 is fine down back too. People are saying Hamling & Cordy aren't tall enough to be KP's, when they will both be 195cm when they have finished growing. I'd be more concerned about our forwards - Boyd 201, Redpath 194 if he makes it, Bonts 194 if he becomes CHF, then Stringer 192, Crameri 189. We would want Roberts or Hamling to make it up forward if Redpath & Bonts don't.

As for the 181-185 glut, who is the best player in the AFL and how tall is he?
 
Interesting stuff on Talia, boydshow .
I double-checked my source (the AFL Record Season guide published about two months after he was drafted and it definitely says 195cm. I agree 192cm is more likely (hence 2cm growth) but who knows.

EDIT:
WB website lists him as 194 cm now, not 195.
http://www.westernbulldogs.com.au/player-profile/michael-talia

Moral - take all measurements with a grain of salt. Whichever ones are correct (if any) they aren't as rigorously done, cross-checked and republished as we fans would hope for.
 
You might be thinking of median (the mid-point in a series of numbers).
It can also be true of an average but it relies on having a fairly even and equal distribution above and below the average. I don't know what the distribution is like in this case.

I don't see that there are in fact any teams in the League whose playing stocks are so out of kilter with the rest as to skew the height average one way or the other.
 
Its an interesting analysis, thanks Dannn..

To me, heightwise, there are two distinct issues, which it seems the stats support

1 - Genuine lack of KP size players (let alone quality KP players, which is a matter of opinion and pure height analysis doesn't touch, but if you look at guys like A Cordy who have been on a our list for years...and other guys not playing ahead of Mark Austin...)

2 - A real cluster of 'smaller' type mids, which this year's draft has exacerbated.

Point 1 - In my view point 1 can be addressed more quickly and readily than point 2 (although it will cost in trade or salary cap). Look at Hawthorn, the taller players they have simply traded or FA'd in include: Gunston, Lake, Hale, Gibson (plays tall), McEvoy, Frawley and Spangher. Not counting Gibson, nearly half of Hawthorn's 193cm and over players have been traded in (and these guys are first 22, while most of their draftees 193cm and over are developing or not that good).

And while its harder for us to attract players than a premiership window team, Hawthorn has demonstrated it is possible to build a list of KPs and rucks via trade and FA (or on the 'fly')

That's not to say I agree with our not picking enough KP size players in the draft, it's just a problem that can be addressed.

Point 2 - Our cluster of smaller mids and flankers really seems harder to address. Yes there are great smaller sub 185cm players, but it seems that in modern footy and against bigger teams, most of these smaller players are restricted to centre or forward of centre. I just don't see how they can all play (or even most of them) and not be exposed for height, particularly when they are dragged back and especially in one on one marking and physical contests where a player of equal of ability but who is bigger should win. It is hard to see how this problem will be addressed easily as if many turn out to be okay it will be hard for us to get them off our list, and we will always be unbalanced and therefore vulnerable.
 
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You seem to have been consistently a couple of years behind the play on this one Butane. We're now consolidating because we now have the cattle with the possible exception of a quality KPD and half back. 2, possibly 3 players doesn't constitute a rebuild. The sensationally successful recruiting matrix that Macca introduced to the club has netted us quality players and leaders like Stringer, Macrae, Hrovat, Bontempelli, Jong etc etc. And treachery and circumstance have netted us a no.1 draft pick KPF (every cloud...).
Beveridge must be ecstatic at the highend quality of the list he's inherited and will no doubt be intent on getting match time/experience into this block of mainly 3rd, 4th and 5th year quality players (Bonts and T Boyd being 2nd year) so that next year when the block is mainly 4th, 5th and 6th year players we'll be ready for a 2013 Port style launch at finals in 2016. And like Port at the end of 2012 and in subsequent years since, a couple of astute off season acquisitions at the end of the year to plug the few gaps that remain.

Satire? Like a good Onion article there is some truth in what you say. 2.5 stars out of 5.
 
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New sections added to part 1 pertaining to the AFL's overall height distribution. I've also adjusted some of the league-wide statistics (eg. AFL average height) as I was using 2014 figures. Now that I have the AFL figures for 2015 I've calculated the average height - slightly lower than last year's figure at 188.30cm.

I've also decided to make dogwatch 's list type suggestion into a different part by itself, which will be up either tonight or tomorrow. That means module 1 will have three parts: overall height distribution (already posted), height distribution by list type, and height distribution by position.

The sections added to part 1, for ease of access, are as follows:

AFL Overall
9rkn54.png

As can be seen in the above histogram, the AFL's peak frequency occurs in the 186-190cm range, with 206 of 817 players (25.21%) fitting within this range. This comes at no great surprise given that the average height in the AFL is 188.30cm - right in the middle of these parameters. Perhaps more interestingly, the next most prevalent height range is 181-185cm - a range that was shown to be less popular amongst back-to-back premiers Hawthorn. 196 players - 23.99% - are between these heights. This is considerably higher than the third-most prevalent height range of 191-195cm, with only 150 players (18.36%) being within these heights. Only 25 of 817 individuals in the AFL player population are under 176cm - a percentage of only 3.06%.

Some other tidbits:
  • The AFL's most frequently occurring height is 188cm. 48 players - or 5.88% of the AFL player population - are 188cm.
  • The AFL's median height is also 188cm.
  • The AFL's standard deviation is 7.39cm.

Western Bulldogs vs. the AFL
Again, a box plot is probably the most fitting here:
2gt6p84.png

Before we get into it, I'll define the outliers present in both plots. Caleb Daniel is the outlier on our column (#44). He's also presented in the AFL column as #226. Brent Harvey (North Melbourne; 167cm), Mason Cox (Collingwood; 211cm) and Aaron Sandilands (Fremantle; 211cm) are the three other outliers.

The box plots indicate that our median is significantly lower than the AFL median - 186cm compared to 188cm. It also indicates a 75th percentile (191.5cm) lower than the AFL's 75th percentile of 193cm, and a 25th percentile (182cm) lower than the AFL's 25th percentile (183cm). This indicates a distribution of heights that centre around a lower midpoint than the AFL's overall distribution. This is also backed up by a difference of approximately 1.5cm between our mean height - 186.83cm - and the AFL's - 188.30cm.

It is interesting to note that our inter-quartile range (that is, the height of the yellow box, or the difference between the 75th and 25th percentiles) is only 0.5cm shorter than the AFL's. In simpler terms, the yellow boxes presented above are approximately equal in size. This means that the middle 50% of our distribution is spread across an approximately expected total number of heights; we don't have too many players bunched within too few heights when you look at the middle 50% in isolation. This does appear, however, to contradict what is shown in the histogram comparisons: that we have a larger-than-expected concentration of players within the narrow limits of 181-185cm.

So what does this mean? My conclusion is essentially that, while we have an acceptable number of players spread in these broader ranges, when you begin to narrow the parameters that you're looking at, it becomes clearer that we're disproportionate to what is expected - both compared to other sides, and to the AFL overall. While our middle 50% of heights cover an appropriate range, the distribution within this range is heavily skewed towards shorter heights. Essentially, our distribution is somewhat similar to the AFL's - just shifted towards shorter heights.

Layman's conclusion: Our overall distribution isn't too dissimilar from the AFL's overall distribution, however, it is more biased towards shorter heights than is expected.
 

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Thanks Dannnn. Two quick questions:
(1) do the AFL averages include the WB? I'm presuming yes, which means it gets pulled down slightly by the WB stats. (Is it easy to calculate the AFL averages without the WB figures included?)
(2) are we the shortest in the AFL on all/any of those measures you discuss ... or don't you have the 18 club-by-club averages?
 
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Thanks Dannnn. Two quick questions:
(1) do the AFL averages include the WB? I'm presuming yes, which means it gets pulled down slightly by the WB stats. (Is it easy to calculate the AFL averages without the WB figures included?)
(2) are we the shortest in the AFL on all/any of those measures you discuss ... or don't you have the 18 club-by-club averages?
1. Yes they do. I realise that this isn't the best way to do things but I had a side interest in the overall distribution for something unrelated and just went with it. I meant to put a note in there about it but forgot. I did run the descriptives however. Without us included the AFL average height increases to 188.39cm (increase of ~0.09cm), median remains the same at 188cm, and the standard deviation decreases to 7.37 (~0.02cm decrease). So it's only a slight effect in the expected direction.

2. I don't know that, sorry. For the purposes of the analysis it was much easier to collectively group all player heights into one 'AFL' category than split them (aside from the three reference teams). It's doable without too much effort given the way I've laid out the data sheet but it's a fair way down the list at the moment.
 
There is a saying I am rather fond of about "dam lies and statistics" in saying that I acknowledge the work that Dan has put in but, the Brisbane list he quotes has Tom Cutler (7) games, Jackson Paine likely to be delisted in 2015 (6) games and Nick Robertson (8) games hardly best 22 players.

Saints fare a little better with Like Delaney (22) but then we have Dylan Robertson (7) games, and McCartin 0

Hawthorn we have Tim O'Brien (4) games and on the rookie list is Kurtz Heatherington 0 games.

Does variables like talent or determination (Dalhousie) have a bigger sway then simply height?
 
1. Yes they do. I realise that this isn't the best way to do things but I had a side interest in the overall distribution for something unrelated and just went with it. I meant to put a note in there about it but forgot. I did run the descriptives however. Without us included the AFL average height increases to 188.39cm (increase of ~0.09cm), median remains the same at 188cm, and the standard deviation decreases to 7.37 (~0.02cm decrease). So it's only a slight effect in the expected direction.

2. I don't know that, sorry. For the purposes of the analysis it was much easier to collectively group all player heights into one 'AFL' category than split them (aside from the three reference teams). It's doable without too much effort given the way I've laid out the data sheet but it's a fair way down the list at the moment.
Thanks Dannn, great work again.

Part of the reason for the second question is I expect some people might say "oh, only 2cm shorter than the median? Only 1.5cm shorter than the average?Hell, 2 cm is nothing!"

My view is that 2 cm is not much to worry about in a single instance (e.g. a player vs player comparison) but is huge if it applies across the entire list. I suspect we are close to the shortest in the AFL on some or even most of these measures.

If, on the other hand, there are a few clubs even shorter than us then at least we can see that we aren't the definitive mosquito fleet and that other clubs are dealing with the same issue (or perhaps taking the same strategic approach).
 
There is a saying I am rather fond of about "dam lies and statistics" in saying that I acknowledge the work that Dan has put in but, the Brisbane list he quotes has Tom Cutler (7) games, Jackson Paine likely to be delisted in 2015 (6) games and Nick Robertson (8) games hardly best 22 players.
Saints fare a little better with Like Delaney (22) but then we have Dylan Robertson (7) games, and McCartin 0
Hawthorn we have Tim O'Brien (4) games and on the rookie list is Kurtz Heatherington 0 games.
Does variables like talent or determination (Dalhousie) have a bigger sway then simply height?
One legitimate criticism of people who only quote statistics* is that they measure the tangibles well, but not the intangibles. How for instance, do you quantify talent or determination?

So I agree with what you're implying: it's a trap to build an entire theory of list management or performance analysis around simple physical measures like height.

Having said that, we'd be silly not to do some analysis of such things, especially when we have some people here arguing we have severely handicapped ourselves by recruiting so many short players. It clearly demands some attention.

On the other matter ...I don't agree with the players you've listed, if you're saying that some of the other clubs' talls are just fringe players. For a start only one is over 193cm (Delaney) and he is now on Geelong's list so is probably not part of Dannn's stats for St Kilda. Secondly some of them are still early in their career (first or second year players) and as talls (or tallish players) the accepted wisdom is they should be given extra time to establish themselves.

My main objection is the same argument could be made for our own list with senior list players like Roberts (7 games in 3 years), Talia (16 games in 3 years), Redpath (3 games in 3 years) and Ayce Cordy (20 games in 6 years - and to the outsider an obvious candidate for delisting in 2015). These four are taller than most of the ones you've listed from other clubs too, so it could be argued we are in fact more susceptible to being downsized!

The bottom line - and the most important point - is that we mustn't forsake common sense and even-handedness when doing statistical analysis. Too often we see people cherry picking the stats to suit their bias or hypothesis, rather than approaching it with an open mind. To my mind it's most effective when we try to find stats to prove ourselves wrong instead of right. If the original hypothesis stands in spite of those efforts then you know you could be onto something.

*EDIT: definitely not to be read as an implied criticism of Dannn!
 
Using 1-3cm differences as proof that players have grown since we drafted them is meaningless. For years, players heights have varied ( up and down) during their careers - often this is due to the method used. And other posters have noted the variances between sources. Unless players are measured each year using the same equipment/location and the same tilt of their head, and the same footwear (or no footwear including socks), there will always be discrepancies. A player starting their career at 192, for example, then being listed at 194 or 195 during their career, may actually retire without ever having grown at all.
 
The thing is, we seem to have a very different list profile in terms of height to most teams. Is this strategic or just the way it worked out? I think this year we got so many smaller types becuase they we were the best available based on the skill set at we needed. Height wasn't the main concideraticon. I'd love to know what the clubs view is on it.
 
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There is a saying I am rather fond of about "dam lies and statistics" in saying that I acknowledge the work that Dan has put in but, the Brisbane list he quotes has Tom Cutler (7) games, Jackson Paine likely to be delisted in 2015 (6) games and Nick Robertson (8) games hardly best 22 players.

Saints fare a little better with Like Delaney (22) but then we have Dylan Robertson (7) games, and McCartin 0

Hawthorn we have Tim O'Brien (4) games and on the rookie list is Kurtz Heatherington 0 games.

Does variables like talent or determination (Dalhousie) have a bigger sway then simply height?
Statistics don't lie as they're only a quantification of things that actually happened - statistics lie when people use them incorrectly. They're only as sound as the conclusions that are drawn from them and in this case I've only drawn very vague comparisons and left most of the interpretation for others to discuss.

In this case I think you're mis-reading the intention of the stats I've given. Some want to draw hard and fast conclusions about what it means for our position; what it means for our results next year; and whether it means we're behind/in front of other teams - but this would be improperly using the statistics as, as you've noted, it does not take into account talent or any other variable such as age or experience. Nobody - especially not me - is suggesting that height is a good independent predictor of success or anything of the sort. I've largely let it slide as I've been interested to read the progression of interpretation on here but I will give some insight into my view of the stats and my intentions now.

First of all, these posts are not at all intended to give us a complete picture of our list build. What they are intended to do is have a look at how we're building our list (in terms of height), and how our strategy compares to other clubs. Note that I'm referring to our strategy at this point moreso than the quality, or balance, of our list. We're unbalanced compared to the AFL average, and compared to other sides - but this shouldn't be interpreted as being an overall poor list strategy, nor should it be considered as putting us on the back foot. We don't know that - there are (at this time) no inferential statistics given to suggest that there's a relationship between height and finishing position, and drawing any such conclusions from what I've supplied would be digging yourself into a hole by misusing statistics.

Here are my thoughts on what this does mean:
  1. Our list strategy brings in more smaller talent than other clubs, on average.
  2. An abundance of players in the 181-185cm range leaves us thinner than expected in taller height ranges.
  3. We have more depth in smaller types than many sides.
  4. We have less depth in taller types than many sides.
  5. We have more chance of finding a competent, AFL-level small than other building sides.
  6. We have less chance of finding a competent, AFL-level tall than other building sides.
What's important to note is that a list with the distribution of ours could very well be just as successful as Hawthorn. We have enough talls to field a side - if they all develop nicely (along with a good portion of our smalls) we could still be an extremely good side. All I'm drawing from the stats is a simple suggestion that we're less likely to find a competent key position player given the distribution of our list. That doesn't mean we can't, just that other sides - like Brisbane - are more likely to than us. But as you've pointed out directly here, quality isn't taken into account and it's possible that our small number of talls are better than Brisbane's large number of talls, for example. Quality will be looked at independently in a later analysis but for now we're looking at height, and height on its own. In terms of numbers, we have less players in the taller ranges and therefore less chance of finding an AFL-level tall.
 
Really enjoyable read Dan(n^n). Looking forward to this thread developing.

Little bit random, but related:

Do you think our height profile may have anything to do with the interchange rules, and trying to build a team light on talls (bare minimum for coverage/functionality) and heavy on runners with skills?
 

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