1st down and 18, the play gains 17 yards but a 5yd penalty is accepted. So we get 1st and 13 as opposed to 2nd and 1? https://mfn30.myfootballnow.com/gamecenter/view/2322#410011

It would seem in this instance it would be better to decline the penalty rather than accepting it but still having over 10 yards left to get a 1st.

Agreed.

I've noticed the AI ALWAYS accepts the penalty if the play does not result in a first down.

Maybe the AI could be set to where if it is 10 or more needed if accepted, vs 3 or less if declined, the penalty would be declined, provided it is not occurring on 3rd or 4th down

Thanks for the example, you are right that this should have been declined in this case, WarEagle is also right that the coach will currently choose a new first down over second (or more) and short. IHP3, thanks also for the suggestion to objectify the decision - I'll need to go with something like that.