Ok I'll explain why I think 20 points is a likely outcome. It's a penalty that is severe enough to be significant (and outweigh the penalties given to Forest and Everton, meaning fans of other clubs can shut up about City not having to take their medicine) whilst simultaneously not actually affecting City that much as with a 20 point deduction they are likely to still qualify for the CL etc.
My hypothesis is based on how businesses operate. Also regarding guilt or otherwise - there are shades of grey always when it comes to legal proceedings and even if you know you are totally innocent there's always the fear that the court/jury etc don't see it that way - maybe the opposition lawyer spins a great story, maybe there's inherent bias on the part of the jury etc.
Which is why I think they won't want to risk it. They'll take a penalty 'in the interests of putting the matter to bed' whilst simultaneously maintaining innocence and stating dissatisfaction with the whole process, both sides move on, and in a couple of years the City fans sit back with popcorn watching Chelsea get bent over a desk by the PL before they go in dry.
All opinion, probably worth fuck all, I've absolutely zero inside info etc.