I've been thinking about how Indian footballers only play 25 odd games a year and the ways in which that could affect their development. Regular football is a must for a footballer's development and the Indian system just does not provide that. So, I thought it would be interesting to see the relationship between age and a footballer's ability.
The lack of football and corresponding lag in development is probably why players like Sunil Chhetri have their primes post the age of 30. The obvious disadvantage to this delayed development is that after a decade of professional football, bodies are no longer optimised for high performance at that age and it requires lot of discipline to keep going.
To see if this is true, I decided to look at the 304k minutes played by 206 different players across the 4 seasons of the ISL. Since match ratings generally don't make sense in football, minutes played is the best proxy for player ability (that I can think of) as good players tend to play more minutes than not-so-good players.
That graph probably asks more questions than it's answers. There's a huge gap between the ages of 25-29, a footballers peak. This could be proof that ISL footballers in their peak age do not get enough playing time as in other stages of their career. There is a secondary peak at the age of 30-31 as most of the foreign signings would fall under that age group.
Note:- This dataset only contains players that played in the last ISL season and their previous appearances in the competition. What this means is that the analysis excludes players like Gouramangi Singh and Alessandro Del Piero, who played in earlier seasons but are not longer part of the league, because I was not able to access the data. IF you are interested in seeing a more complete version of this analysis and you have access to minutes played data for every player to ever play in the ISL, reach out! If you have I-League data, even better!
I corrected for the above by only looking at 200k minutes played by 131 Indian players across the 4 season history of the Indian Super League. While this isn't necessarily as complete as I'd like, I think it serves as a decent enough sample.
The above curve more closely resembles previous research into this subject and the peak age of an Indian footballer comes out as 25. There is also a gradual rise and fall to the curve that indicates that my initial hypothesis that Indian footballers go through stunted development may not necessarily be true. There is a plateau in minutes between ages 28-30 indicating that players in that age group generally receive the same amount of game time.
There's a dramatic rise in minutes played when one goes from 19-20 and an equally steep drop from 30-33. The latter is probably because ISL teams prefer to carry multiple 30 year old foreigners in the team and would probably not want to skew the age ratio in their squads. To check this hypothesis, I split the minutes played of Indian players by positions.
After the "peak age" between 24-26, we see a tremendous drop in Indian midfielder and forward minutes and the exact opposite in defender minutes. 26 seems to be a bad age for defenders (due to my limited data) but other than that they generally see solid minutes between the ages of 24 and 31. Midfielders and forwards don't get the same luxury as foreigners are preferred in those positions and, in their absence, younger Indians.
Note:- Due to subjective nature of positions, I just used the definitions on the ISL website. For example, a player like Baljit Sahni is listed as a FWD even though most of his minutes last year came at RB. He's a versatile guy and can play both the positions but we proceed with him officially listed as a FWD.
So to conclude, it's pretty clear the data that there are two trends in the ISL,
Indian footballers receive less game time than footballers in other countries but there is no evidence that this stunts their performance or creates a delayed peak
Indian midfielders and forwards above the age of 26 face stiff competition from foreigners for minutes which is a threat to their development
Squad rules & foreign player restrictions ensure that Indian defenders outnumber Indian players in other positions and as a result see more consistent game time
