Question: when did the red sox yankees rivalry began
[{'answer': '1919', 'provenance': [{'wikipedia_id': '1141484', 'title': 'Yankees–Red Sox rivalry', 'start_paragraph_id': 1, 'start_character': 275, 'end_paragraph_id': 1, 'end_character': 279, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1141484', 'title': 'Yankees–Red Sox rivalry', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 585, 'bleu_score': 0.9496016038707511, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12196900291456372707}, 'section': 'Section::::Abstract.'}]}]