The development of players

[micvik]

I have a few questions on how players develop:

Is there a potential rating that influences their development?

Do players develop only in training camp or also during the season?

Does age effect the rate at which they develop?

*side question:
What are the R17,R18,R19 and R20 ratings used for?

[David Winter]

Is there a potential rating that influences their development?

 
Yes. There's a table in the DB that stores this information, but it's not exposed anywhere in the front end. It's purposefully done that way because hidden potential is well.. hidden

Do players develop only in training camp or also during the season?

 
They develop during training camp, they decline at the end of the season.

Does age effect the rate at which they develop? 

 
It effects the rate at which they decline. At some point, training camp will only be offsetting what they lost at the end of the season.. shortly after that, they'll always be in decline now matter how much they train.

*side question:
What do the R17,R18,R19 and R20 ratings used for?

 
They're not used for anything at the moment. A long, long time ago, they were used but their use never made it into public builds. I left them in the database because should the need arise, they're there if I need them and I don't need to rebuild them.