From ATP 2011 Rule Book : B.Entries
Selection List. The selection list for the event shall be:
- a) The top seven players in the South African Airways ATP Rankings as of the Monday after the last ATP World Tour tournament of the calendar year; followed by
- b) Up to two Grand Slam winners of that year, in order of their positions, positioned between eight and twenty in the South African Airways ATP Rankings as of that Monday; followed by
- c) Players positioned eight and below in the South African Airways ATP Rankings as of that Monday.
Direct Acceptances. The top eight players in the selection list shall qualify for the event as direct acceptances. Participation is mandatory, and all qualified players shal be entered. All direct acceptances must be at the tournament site to attend the official pre-tournament media conference and must be available for play through the completion of the round robin competition and the knock-out competition if eligible.