If I want my starting offensive linemen to stay in the game almost every play, do I set my sub level at 95 or 60? Also, I realize the tackle position is your most dominate offensive linemen, but what factors do you guys give to the center position and what factors do you take into consideration in regards to where to place your best to worst players along your depth charts at all positions? Thanks in advance...

If you want players to stay in longer you set the sub level lower. I personally don't go below 85 but that is your choice where you stop.

As far as your OL question... the OL is actually simulated as a "unit" and not as individual players like all of the other positions so it truly doesn't matter where you have players listed as far as G vs T vs C.

At D3 , you would want to make sure that OL, that you want to get as much playing time as possible, is in the first 5 players in the OL depth chart collum, D2 and higher you have more options with the user 1 and 2 spots... Check the formations tab to see which spot correlates to depth charts, again more relevant in D2 and up. Just a thought ... If that OL is not as good as say 5 other OL set him at 6th on the depth chart and a lower sub % and the other "better" 5 at say 90% or 95 depending on their stamina.

I would not sub lower than 85, your player will stay in and is tired, especially in the 4th QT, you will get killed.

can i change it at halftime

i mean i know i can, but will it take

Yep, it will take.

Thanks guys for the help. It is great how much you guys help. I have three to five players that I Ned to play as much as possible as they are definitely my best players. I have left my settings on 85 across the board up to this point and rotated my younger players in on occasion (especially early in the season), but now that I am in the playoffs I would like to have my obviously best players on the field as much as possible without them wearing out from fatigue. I understand their ratings tell me how long they should go, but not sure exactly how this will equate in game situation. Many have said, including in this thread, that you guys do not go below 85. How do I get the most out of my best players if I do not set their sub level below 85? I am asking because I would like to give my team the best chance of succeeding in the playoffs and hopefully not have to wait until next season to test. Thanks again for all of your help guys and I will check back a little later for your advice so I can implement it in tonights game...

"How do I get the most out of my best players if I do not set their sub level below 85?"

You get the best out of your players by setting them at 95 -- they play at 100% down to 95% of capacity.
You get almost as good play out of your players by setting them at 90 -- they play at 100% down to 90% of capacity.
You get almost as good as that by setting them at 85 -- they play at 100% down to 85% of capacity.
Lots of coaches don't want their players playing below 85%.

So the question is not only how to get the best out of your players, you have to recognize when the sub at 100% is as good as your fatigued starter. That's where the balance becomes delicate. Good luck.