Tennis legends disagree on nature of ATP World Tour events . Roger Taylor argues the case for an indoor tournament while Murray wants an outdoor tournament . 2013 tournament got underway on Monday as Stanislas Wawrinka beat Tomas Berdych . Juan Martin del Potro rallied to beat Richard Gasquet in the evening session .
Tennis legends disagree on nature of ATP World Tour Finals . Roger Federer argues the case for an indoor tournament while Nadal wants an outdoor event . 2013 action got underway on Monday as Stanislas Wawrinka beat Tomas Berdych . Juan Martin del Potro rallied to beat Richarg Gasquet in the evening session .