I realy only have 1 thing to say, and it's the same I am selling for many seasons now.
there is no such thing as optimal minutes, and if there was, and it sure is not 60 !
I am playing this game from season 3 (end of season 2 to be exact, but I had no more games to play in that season when I entered the game) and NEVER have I been playing my players up to 60 minutes. Okay it happened occasionally. But most of the time my players got between 43 and 55 minutes and I have always had very good shapes, of 8 or 9, with a few 7's among them.
Based on my personal experience any amount of minutes played between 46 and 51 is the best possible amount. More won't hurt, but it will not be better and it often means you loose trainingminutes. The total area to stay in would be 46 to 70 minutes to be good.
Less gives a higher chance to drop, more as well. The further away from that area the bigger the chance.
Read carefully, chance, so it doesn't have to happen.
Minutes from past weeks also count. this means that if a player has played for 60 minutes and next week he gets 40, chances are good he even increases, while 2 more executive 40 minutes weeks would likely make him drop.
Same for high numbers, playing a player 5 times in a row for 71 minutes will have more chance to drop the guys shape, then 4 times of 44 to 55 minutes and 1 week 80 minutes.
As it is all based an chances, it if very hard to make correct science and give the right numbers on all this. But for the few that aren't rusted into believing the optimal amount is between 55 and 65, they might try out and see for themselves.
Last season I trained a rookie and I had him play exact 48 minutes most of the weeks. He has had a 9 on GS for the entire season. This season I have less luck and often need to play him 2 games a week, so he averages somewhere between 55 and 65 minutes each week, and he has been 7 for the entire season, until this week...
It's not just him, I have been experiencing this snice my start of this game. And while 65 minutes might not hurt GS, claiming less then 55 is just clearly wrong.
Some periods it doesn't seem to work whatever you do, or how many minutes you have them play, they just won't go up. It's called bad luck (or maybe it also works in periods), but after being here for 12 seasons I think I know what I'm talking about when I talk about minutes and GS.
They are not your friends; they dispise you. I am the only one you can count on. Trust me.