The draw is random, based upon seedings. It works like this:
You make one half of the draw the #1 half, the other is the #2 half. The player seeded #1 goes in the #1 half, the player seeded #2 in the #2 half.
Now, you seed randomly the remaining seeds as follows: each of the remaining half of the next larger power of 2 are seeded randomly opposite the already seeded players. Thus, #3 and #4 are seeded randomly to be in the #1 or #2 halves; #'s 5 to 8 randomly in the four quarters of the draw, #'s 9 to 16 in the eight eighths of the draw, and #'s 17 - 32 in the 16 sixtheeths of the draw. The remaining 96 players are then placed randomly in the remaining slots. Thus, as you look down the pairings starting from the top, each group of four players (split into two matches, the winners of which meet in Round 2) will have one seeded player, and three unseeded players. Seeded players cannot meet until Round 3, and if/when they meet, all such meetings will be between someone from the top half of the seedings vs. someone from the bottom half of the seedings (1 to 16 vs. 17 - 32). After that, it’s someone from 1 to 8 vs. someone from 9 - 16, unless one of the top 16 was upset in a prior round, and thus it continues to the end.
So if the tournament holds to seeded form, the last round is 1 v 2, but the semis can be 1 v 3 or 1 v 4, the quarters can be 1 v 5, 6, 7, or 8, and the octos (Round of 16 they sometimes call it here in the States) will be 1 v 9, 10, 11, 12, 13, 14, 15, or 16.
ETA: Men’s draw is here.
And should add that this system is slightly skewed now because they took the #5 seed, put him in the #1 hole, and moved a few others around, due to withdrawls.
