This article is from the Table Tennis (Ping Pong) FAQ, by ttennis@bu.edu with numerous contributions by others.
4.5.1 Byes and Qualifiers
4.5.1.1 The number of places in the first round proper of a knock-out event
shall be a power of 2.
4.5.1.1.1 If the number of places is greater than the number of entries
accepted, the first round shall include enough byes to make up the
required number of places.
4.5.1.1.2 If the number of places is smaller than the number of entries
accepted, a qualifying competition shall be held such that the number
of qualifiers and the number of entries excused from the qualifying
competition together make up the required number of places.
4.5.1.2 Byes shall be distributed as evenly as possible throughout the first
round, the byes being placed first against seeded places, in ranking
order.
4.5.1.3 Qualifiers shall be drawn as evenly as possible among the halves,
quarters, eighths or sixteenths of the draw, as appropriate.
4.5.2 Seeding by Ranking
4.5.2.1 The highest ranked entries in an event shall be seeded so that they
cannot meet before the closing rounds of the competition.
4.5.2.2 The number of entries to be seeded shall be a power of 2, determined
by the number of entries in the first round, as follows:
4.5.2.2.1 for up to 24 entries there shall be 2 or 4 seeds;
4.5.2.2.2 for 25 to 48 entries there shall be 4 or 8 seeds;
4.5.2.2.3 for 49 to 96 entries there shall be 8 or 16 seeds;
4.5.2.2.4 for 97 or more entries there shall be 16 or 32 seeds;
4.5.2.2.5 for World Championships singles events there shall be 32 seeds;
4.5.2.3 The 1st ranked entry shall be placed at the top of the first half of
the draw and the 2nd ranked entry at the bottom of the second half,
but all other seeded entries shall be drawn by lot among specified
places in the draw, as follows:
4.5.2.3.1 the 3rd and 4th ranked entries shall be drawn between the bottom
of the first half of the draw and the top of the second half;
4.5.2.3.2 the 5th to 8th ranked entries shall be drawn among the bottom
places of the odd-numbered quarters of the draw and the top places
of the even-numbered quarters;
4.5.2.3.3 the 9th to 16th ranked entries shall be drawn among the bottom
places of the odd-numbered eighths of the draw and the top places
of the even-numbered eighths;
4.5.2.3.4 the 17th to 32nd ranked entries shall be drawn among the bottom
places of the odd-numbered sixteenths of the draw and the top places
of the even-numbered sixteenths.
4.5.2.4 In a team knock-out event only the highest ranked team from an
Association shall be eligible for seeding by ranking.
4.5.2.5 Seeding by ranking shall follow the order of the latest ranking list
published by the ITTF except that
4.5.2.5.1 where all the entries eligible for seeding are from Associations
belonging to the same Continental Federation the latest list
published by that Federation shall take precedence;
4.5.2.5.2 where all the entries eligible for seeding are from the same
Association the latest list published by that Association shall
take precedence.
4.5.3 Seeding by Association Nomination
4.5.3.1 Nominated players and pairs from the same association shall be
separated in the draw so they cannot meet before the closing rounds.
4.5.3.2 Associations shall list their nominated players and pairs in descending
order of playing strength and this order shall be used for seeding by
Association unless it differs from the order used for seeding by
ranking, when the latter shall be used.
4.5.3.3 The players or pairs ranked 1 and 2 shall be drawn into different
halves and those ranked 3 and 4 into quarters other than those
occupied by the first two; whenever possible, those ranked 2 and 3
shall be drawn into the same half.
4.5.3.4 The players or pairs ranked 5-8 shall be drawn into eighths other than
those occupied by the first four, with 5 and 6 in opposite halves and
7 and 8 in opposite halves; the players or pairs ranked 9-16 shall be
drawn as evenly as possible into sixteenths other than those occupied
by higher ranked players or pairs and so on, until all the entries have
been allocated.
4.5.3.5 A men's or women's doubles pair consisting of players from different
Associations shall be considered a pair of the Association to which
the player ranked higher in the World Ranking List, or, if neither
player is in this list, in the appropriate Continental Ranking List
belongs; if neither player is included in a World or Continental Ranking
List, the pair shall be considered a member of the Association whose
team is ranked higher in the appropriate World Team Ranking List.
4.5.3.6 A mixed doubles pair consisting of players from different Associations
shall be considered a pair of the Association to which the man belongs.
4.5.3.7 In a qualifying competition, entries from the same Association, up to
the number of qualifying groups, shall be drawn into separate groups
in such a way that qualifiers are, as far as possible, separated in
accordance with the principles of 4.5.3.3 and 4.5.3.4.
4.5.4 Alterations
4.5.4.1 Alterations to a completed draw may be made only with the authorisation
of the responsible management committee and, where appropriate, the
general agreement of the representatives of the Associations directly
concerned.
4.5.4.2 The draw, once completed, shall not normally be altered except
4.5.4.2.1 to correct errors and genuine misunderstandings in notification and
acceptance of entry;
4.5.4.2.2 to correct serious imbalance, as provided in 4.5.4.7;
4.5.4.2.3 to include additional players or pairs, as provided in 4.5.4.8.
4.5.4.3 No alteration other than necessary deletions may be made to the draw of
an event after play has started in that event; for the purpose of this
regulation a qualifying competition may be regarded as a separate event.
4.5.4.4 No player may be deleted from the draw without his permission, except
for disqualification by the referee for reasons within his jurisdiction;
such permission shall be given in writing, either by the player
personally if he is present or by his authorised representative if he
is absent.
4.5.4.5 No alteration may be made to a doubles pair if both players are present
and fit to play; injury, illness or absence of one player may be
accepted as justification for an alteration.
4.5.4.6 No entry shall be moved from one place in the draw to another, except
that if, in circumstances such as the withdrawal of a large proportion
of the entries the event becomes so unbalanced that re-arrangement is
necessary it shall, wherever practicable, be completely re-drawn in
accordance with the original procedure.
4.5.4.7 Exceptionally, where the imbalance is due to the absence of several
seeded entries from the same section of the draw and a complete re-draw
is impracticable, the remaining seeded entries may be re-numbered in
ranking order and re-drawn to the extent possible among the seeded
places, leaving the remainder of the draw unchanged; in applying this
procedure, priority shall be given to the requirements for seeding by
Association nomination.
4.5.4.8 Players not included in the draw may be added later, at the discretion
of the responsible management committee and with the consent of the
referee, in accordance with the following procedure:
4.5.4.8.1 Any vacancies in seeded places shall first be filled in ranking order,
by drawing into them the strongest additional entries.
4.5.4.8.2 if the number of additional entries is smaller than the number of
vacancies in seeded places, these vacancies shall be filled in
ranking order to the extent possible.
4.5.4.8.3 if the number of additional entries is greater than the number of
vacancies in seeded places, the remaining entries shall be drawn
first among vacancies due to absence or disqualification and then
among byes other than byes against a seeded entry.
4.5.4.8.4 Entries who, if included in the original draw, would have been
eligible for seeding by ranking may be added only if there are
sufficient vacancies in seeded places.
4.5.4.8.5 The allocation of additional entries shall take account as far as is
practicable of the requirements for seeding by Association nomination.
 
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