"More off base" refers to being more incorrect, mistaken or wrong about something. Antonyms for this phrase would include "accurate," "correct," "precise," "exact," and "right." These words indicate an understanding that is in line with reality and that is well-supported by evidence. Other possible antonyms for "more off base" include "on target," "spot-on," "well-informed," "wise," and "informed." These words suggest that the speaker or writer has taken the time to research and understand an issue in depth, and that their opinion is well-informed and trustworthy. Overall, the antonyms for "more off base" describe a person or idea that is trustworthy, accurate, and well-supported.