How tennis seeding works, and why draws are not random

A tennis seeding is not a second ranking. It is a reserved place in the draw, given to the highest-ranked players so the leading names cannot meet in the first round. In a Grand Slam singles draw of 128 players, 32 of them are seeded, which is one quarter of the field.

A seed is a position, not a ranking

The Grand Slam Rule Book describes seeds as players who are given preferential positions in the draw. Those positions sit on fixed lines and the rest of the field is drawn around them. The number beside a name on the scoreboard is that player's seed, and it matches their world ranking only when every leading player enters the event.

When some of them skip a tournament, the two numbers separate. If the world number one does not enter, the best-ranked entrant is seeded first whatever their ranking says, and a player ranked eighth can be seeded second. The proportion holds across the sport: a 128-line draw carries 32 seeds, a 64-line draw usually 16, and a 32-line draw eight.

How the seed positions are filled

Seed one goes on the top line of the draw and seed two on the bottom line, placing them in opposite halves, so they can only meet in the final. Seeds three and four are then drawn and placed on set lines in opposite halves, so each half holds two of the top four and each quarter holds one.

That logic continues down the list: bands of seeds are spread so no section of the draw collects two players from the same band. A seed's first match against another seed therefore arrives in the later rounds, while the early rounds pair them with opponents who came in on ranking, through qualifying or on a wildcard. The full procedure is published in the itftennis.com Grand Slam rule book.

Which ranking list is used

Entry is settled well before the draw is made. 104 of the 128 places in a singles draw are direct acceptances based on ranking at an entry deadline about six weeks before the event, and the rest go to qualifiers and wildcards. Seeding is calculated later, from the rankings published at the start of the week the draw is conducted, as the official ausopen.com explainer sets out. A good run in the days before the tournament can therefore still move a player up or down the seed list.

What seeding does and does not promise

Seeding is a balancing device, not a forecast. It keeps the strongest entries apart, gives every quarter a comparable standard and rewards past results with a gentler opening. Nothing is guaranteed once play starts: seeds lose in the first week and qualifiers reach the second.

The bottom line: a seed is a fixed place in the draw, not a rating. Thirty-two players in a Grand Slam singles field get one, the top two are kept apart until the final, and every other position follows a published procedure.