From Longman Dictionary of Contemporary Englishdo something off your own batdo something off your own batINDEPENDENT PERSON British English informal to do something without being told to do it She went to see a solicitor off her own bat. → bat
Examples from the Corpus
do something off your own bat• He had made the most ancient blunder in the business quite off his own bat.• Instead, off her own bat, the girl went to see a solicitor in Newton Abbott, Devon. 