Complex sentence: In 2009, he broke the record for the most wins in a calendar year, winning 86 out of 90 bouts, and repeated with the same record again in 2010 when he established the second longest winning streak in sumo history.
Split into simpler sentences: In 2009, he broke the record for the most wins in a calendar year, winning 86 out of 90 bouts, and repeated with the same record again in 2010. In that year he established the second longest winning streak in sumo history.