This article is from the Table Tennis (Ping Pong) FAQ, by ttennis@bu.edu with numerous contributions by others.
18.1 The expedite system shall come into operation if a game is
unfinished after fifteen minutes' play unless both players or pairs
have scored at least 19 points or at any earlier time at the
request of both players or pairs.
18.2 Under the expedite system each player shall serve for one point in
turn, and if the service and twelve successive good returns of the
serving player or pair are each followed by good returns of the
receiving player or pair, the server shall lose a point.
18.2.1 If the ball is in play when the game is interrupted, play shall
restart with service by the player who served in the rally that was
interrupted.
18.2.2 If the ball was not in play when the game was interrupted, play
shall restart with service by the player who received service in
the immediately preceding rally.
18.3 Once introduced, the expedite system shall remain in operation for
the remainder of the match.
 
Continue to: