407.3. The player is designated and the choice of playing first is made during the Start of Game procedure. See CR 115 Determine turn order.
407.4. For games after the first game of a match, the loser of the previous game gets to choose if they play first or last. If the previous game was a draw, the starting play from the previous game is maintained.
407.5. For alterations to this rule for 2v2, see 603.7.