Also there is no need at all to question the rules time by time, which seems to be one of your favorites (forgive me if I'm wrong). The rules are right, unless proven wrong.
in my eyes the past effect of the last week is the current game shape ;)
Or did you get a player with GS 3 in one week to GS 9 with optimum minutes, i say no like you don't get a player within one week to GS 3. So my modell clearly fit with the rules.
Since the game shape is reset at offseason there is no way to conclude anything about the influence of past weeks from that research, since the past weeks can't be included in there due to the reset.
the different progress of same minutes, seems to me a clear factor for randomness especially because there aren't no past weeks - thats why i choose that ;)Later on the gs seems to be behaven foor me like at the beginning.
Even i don't expect a bad background form for player who have from beginning on good minutes.