Question: who is the most successful team in nba history
[{'answer': 'The Boston Celtics', 'provenance': [{'wikipedia_id': '22093', 'title': 'National Basketball Association', 'start_paragraph_id': 78, 'start_character': 0, 'end_paragraph_id': 78, 'end_character': 18, 'bleu_score': 1.0, 'section': 'Section::::Championships.\n'}]}, {'provenance': [{'wikipedia_id': '22093', 'title': 'National Basketball Association', 'start_paragraph_id': 78, 'start_character': 0, 'end_paragraph_id': 78, 'end_character': 407, 'bleu_score': 0.663710933107569, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10965249469578269170}, 'section': 'Section::::Championships.\n'}]}]