ITF junior/ Pro career ranking comparisions/ co-relation

[Atithee]

Thanks Sameer. I can’t believe how much work we collectively did on this topic. Where is Kujo now a days? Is he still even logging in? I miss him in the forum as I used to look forward to his posts so much in the olden days.

[sameerph]

Yes, missing him. He last posted almost a year back in Feb. 2017.

[sameerph]

So, getting back to Vishnu's question yesterday regarding Yuki -

There are a lot of Jr WR#1 who have not even made it beyond ranking 150 as a pro (I wish there were stats around this somewhere or someone with access to that db).

This is the analysis of year end ITF top 2 players from 2001 to 2015 and where they reached at their carrer high ATP rankings -

2001 Career high ATP rankings
Giles Muller 59
Janco Tipsarevic 8
2002
Richard Gasquet 7
Marcos Baghdatis 8
2003
Marcos Baghdatis 8
Joe-Wilfred Tsonga 5
2004
Gael Monfils 6
Eduardo Schwank 48
2005
 Donald Young 43
Marin Cilic 4
2006
Thiemo De Bekker 40
Nicolas Santos 473
2007
Ricardas Bernakis 50
Uladzmir Ignatic 129
2008
Yang Tsung Hua 187
Yuki Bhambri 88
2009
Daniel Berta 691
Gianni Mina 219
2010
Juan Sabestian Gomez 469
Marton Fuscovics 80
2011
Jiri Vesely 35
Luke Saville 152
2012
Philip Peliwo 183
Kimmer Coppejans 97
2013
Alexander Zverev 3
Borna Coric 33
2014
Andrey Rublev 32
Orlando Luz 450
2015
Taylor Fritz 53
Casper Rudd 108

[sameerph]

So, out of 30 players who finished within top 2 in the year end ITF junior rankings from 2001 to 2015, 14 went on to reach top 50, i.e almost 50% of them, 8 of them reached top 10. 20 of them reached at least top 100, i.e almost 2/3rd of it and only 8 could not even reach top 150 which about 25%.

So, Yuki is somewhere below top half of the players but ahead of bottom quarter of players among these in terms of rankings at ATP level.

It also needs to be noticed that there were only 2 Asian players who have finished among top 2 in all those year and the other one apart from Yang Tsung Hua who never reached top 150.

Considering lack of support to Yuki and his injury history, he has had a fair career so far compared to his junior achievements. We can realistically expect him to be in top 100 and be around 50-100 ranking level for most of next 5 years or a little more. Anything beyond that will be a surprise. Below that and him remaining in 100-150 range for major part ( or below that) will be disappointing.

[VReddy]

Thank you for the super useful analysis - Sameer. You are so on top of things as usual . Amazing stuff. Based on your data, here is data based on Jr Grand Slam Winners and it points to the same trend as you have highlighted - sharing for future reference: https://docs.google.com/spreadsheets/d/ ... 1245257408

Thanks again!

[sameerph]

Thanks, Vishnu. Yes, even that data confirm that Yuki is somewhere in the third quarter of the players who have had similar level achievements in juniors. Considering his lack of support and all, it is a fair position which he has reached.

[jayakris]

By the way, , does the word co-relation really exist? It possibly does exist, but I am unsure if it means exactly the same as correlation. It's not there in all dictionaries. Should I change the title to "correlation"? But then again, it is a statistical concept and we are not really talking about any correlation in this thread,...

[sameerph]

Yes, you can change the title to something else of co-relation is not a word at all and correlation is not appropriate here. Perhaps, we can change it to analysis.

[Varma]

This is the meaning of correlation and a few related examples from Oxford Dictionary...

correlation (NOUN)

Mutual relationship or connection between two or more things.
‘research showed a clear correlation between recession and levels of property crime’
[mass noun] ‘there was no correlation between the number of visits to the clinic and the treatment outcome’

[mass noun] The process of establishing a relationship or connection between two or more things.
‘the increasingly similar basis underlying national soil maps allows correlation to take place more easily’

Statistics [mass noun] Interdependence of variable quantities.

Here in our context, we are talking about how a higher junior ranking of a player is related/reflected in their senior ranking, so "correlation" can be used, no?

- Varma

[prasen9]

There seems to be an entry in an online dictionary for the term co-relation. co-relation In this case, the calculations are not what is known in statistics as correlation (or more accurately correlation coefficient, which is colloquially termed correlation). In a broad sense, this is correlation and not the correlation coefficient. But, after all, I support changing the title to drop the term co-relation and replace it by "analysis".

On the topic, I think Yuki never achieved what he could because of his injuries. I guess people do not have the time to do another analysis like what Sameer did but I am taking a guess.

In American sports, people use a stat called WAR (wins over replacement), that is what the player has achieved and how much better it is than a replacement player. In tennis, we can use the replacement player to be world #200 or #100 for elite players, etc. Then, they add it up over the years. So, if you have played five years of basketball as a #6 player, you get a certain value. And if someone has only 1 season of all-star calibre but got injured and retired, they get a certain value. Comparing the WARs over years gives us some objective idea of how useful/valuable the player has been to the team. Different sites have slightly different formulae and different terms. For example, in basketball they use the term VORP but it is a similar concept. Maybe we need such a term for tennis. Anyone seen any advanced stats site for tennis?