Question: former world number one tennis player who coached roger federer in 2014
[{'answer': 'Stefan Bengt Edberg', 'provenance': [{'wikipedia_id': '391932', 'title': 'Stefan Edberg', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 19, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '391932', 'title': 'Stefan Edberg', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 709, 'bleu_score': 0.8447589919309171, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5115967531464476588}, 'section': 'Section::::Abstract.'}]}]