This article is from the Table Tennis (Ping Pong) FAQ, by ttennis@bu.edu with numerous contributions by others.
The draw, or seeding, is one of the most important elements of a successful
tournament. The two principal purposes of the draw are to systematically
select and separate the top players and separate as much as possible
players from the same area. In round-robin events, seeding is normally
limited to one or two players into each of the groups.
After the draw is posted, no change can be made without the consent of all
players affected by any proposed change. Once play has begun in an event,
no change can be made in the draw of that event.
 
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