I think game shape is too important in buzzer for luck to play such a role in it.
For example my best player with the same stamina from 2.970 (9 game shape) with 79 min went to 1.665 DMI. Of course 79 min isnt the best but also not the worst so it would be better in this cases a smaller drop.
But 3 weeks later, with excellent minutes (67, 63, 70) he is respectable at 1.160!
Its okay for luck to play a small role, but when you rotate in one of the two league games of the week so you can have better game shapes and in some cases you have worst it makes you wonder.
I had a psychologist for a while, but didnt see a big difference. May i have to rethink it.
And of course this is one example. I also had players that didnt go to 9 game shape all season, but can happen from time to time.
All in all i would recommend when a players gets good min and his gameshape is 7 or a bad 8 AT LEAST to not fall. Is something that it is possible?