Price of tickets!

[SimplySimon]

Depends if your 'ideal' is more money or more possession bonus - if money then raise price of ticket by 1 until revenue hits peak, if possession then raise by 1 until you drop under full capacity

But be prepared for crowds to fluctuate, because lower quality teams attract fewer fans (like real life)

If you want to play it safe for maximum possession bonus, just keep prices low because the match day revenue is tiny for the first few seasons anyway - you'd get more from watching one video