I'm sure your coaching staff's skills are intended to be a prime component but my observations do not confirm this.
From watching 17 seasons it seems that production and rating progress are closely related. Some positions award production for attendance and others are extremely difficulty.
Furthermore, there appears to be a link between learning and stat progress. Maybe learning gets play knowledge which gets better performance which gets accelerated production.
What's up?
PS, I found this in MRS post which directly addresses my original question, thanks MRS.
Players with high learning abilities will receive more progression points. These guys will reach their potential very quickly.

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