They never said the plus or minus it will go. If you google a conversation between Joel doonan and nephenthez I know it was Joel who is a dev though. I can’t remember if it was nep though but Joel was the important person that matters.
He said rage quits count for plus and minus as at that time people thought if you quit your form wouldn’t change.
But the part that answers your question he said on 12-12 it’s possible to play someone who is 12-6 and also someone who is 11-5. So you know it searches at least that wide of a range. It was in the older fifas so how wide it searches today I don’t think they said. I assume it’s still not exact form though.