question: Who had a better single career ranking, Rohan Bopanna or Jim Grabb ?
answer: Jim Grabb
context: Title: Gabriela Dabrowski
  Passage: Gabriela Dabrowski (Polish: "Dąbrowska" ; born April 1, 1992) is a Canadian professional tennis player.  She reached her highest WTA singles ranking of 164 on November 3, 2014 and her highest doubles ranking of 18 on September 11, 2017.  She won the 2017 French Open mixed doubles title with Rohan Bopanna, becoming the first Canadian woman to win a senior Grand Slam title.
  Title: 2013 BNP Paribas Masters – Doubles
  Passage: Mahesh Bhupathi and Rohan Bopanna were the defending champions, but Bhupathi decided not to participate.  Bopanna played alongside Édouard Roger-Vasselin.
  Title: 2012 Gerry Weber Open – Doubles
  Passage: Rohan Bopanna and Aisam-ul-Haq Qureshi were the defending champions but Bopanna decided not to participate. <br>
  Title: 2014 Open 13 – Doubles
  Passage: Rohan Bopanna and Colin Fleming were the defending champions, but Bopanna chose not to participate.  Fleming played alongside Ross Hutchins, but lost in the quarterfinals to Marin Draganja and Mate Pavić. <br>
  Title: Rohan Bopanna
  Passage: Rohan Bopanna (born 4 March 1980) is an Indian professional tennis player.  His singles career high ranking was World No. 213 in 2007 and his career high ranking in doubles was World No. 3 on 22 July 2013.  Recently, most of his appearances in professional tournaments have been in doubles matches.  He is a member of the Indian Davis Cup team since 2002.  In 2010, he finished as a runner-up in doubles at the US Open, partnering with Aisam-ul-Haq Qureshi.  He won the 2017 French Open - Mixed Doubles title with Gabriela Dabrowski of Canada becoming the fourth Indian player to win a Grand Slam title.
  Title: 2009 LA Tennis Open – Doubles
  Passage: Rohan Bopanna and Eric Butorac were the defending champions, but Bopanna did not participate that year. <BR>Butorac partnered with Scott Lipsky, but lost in the first round to Denis Istomin and Leonardo Mayer. <BR>Bob Bryan and Mike Bryan won in the final 6–4, 7–6 against Benjamin Becker and Frank Moser.
  Title: Jim Grabb
  Passage: Jim Grabb (born April 14, 1964) is an American former professional tennis player.  He was ranked the World No. 1 doubles player in 1989 and in 1993.  Grabb's best singles ranking was World No. 24, a ranking he achieved in February 1990.
  Title: 2012 If Stockholm Open – Doubles
  Passage: Rohan Bopanna and Aisam-ul-Haq Qureshi were the defending champions but Bopanna decided not to participate. <br>
citations: Rohan Bopanna Jim Grabb