With regards to rolling subs we originally assumed that you never find the time to record exactly who was replacing who and when and keep track only of starters, used subs and non-used subs.
If some of you do want to go to this level, we have also assumed that it is to calculate the number of playing minutes each player has (why else?).
We did consider issues regarding rolling subs in our initial design but concluded that we could not suitably reflect data at this level in the end of season memorabilia and would really be collecting data for data's sake ( a trap into which several web 'services' have fallen!).
In response to some manager's comments regarding the issue of rolling subs, we have enhanced the site to allow managers to record the number of playing minutes for each player per match if they so wish (Report, More details).
We trust this is sufficient. Let us know if it's not!