Question: when did nba change to best of 7
[{'answer': '2014', 'provenance': [{'wikipedia_id': '12106552', 'title': 'NBA playoffs', 'start_paragraph_id': 5, 'start_character': 266, 'end_paragraph_id': 5, 'end_character': 270, 'bleu_score': 1.0, 'section': 'Section::::Format.\n'}]}, {'provenance': [{'wikipedia_id': '12106552', 'title': 'NBA playoffs', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 361, 'bleu_score': 0.7284586982423621, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9340700477847368393}, 'section': 'Section::::Format.\n'}]}]