Seeding and the draw

Where the ranking comes from

It differs by sport, and the source is always written down.

Two families are visible. Some sports seed from a ranking built over months. Others seed from something done at the event itself, a time trial or a qualifying round, so that today's form decides.

The athletics rules add a caution. Training performances, and ideas about what an athlete "might be worth", are not to be used.

Who decides

The ranking does not seed anybody by itself. Somebody applies it, and the rule books name them.

In para badminton it depends on the grade of tournament: the Badminton World Federation seeds its Grade 1 and 2 events, and the continental confederation of the host country seeds Grade 3 events and continental championships. In rowing, the Executive Committee publishes the seeding criteria in advance and appoints a Seeding Panel, which decides which crews in which events are seeded. USA Pickleball leaves seeding to a committee.

In boxing the question is one step earlier. Whether a competition is seeded, and how many boxers are seeded in each weight category, is decided for each event and announced in the event invitation. In BMX racing the organiser may choose among several methods, including a random one, and must say which in the event's technical guide.

Five ways of using it

Keep the strongest apart. This is bracket seeding. In a Grand Slam draw of 128, Seed 1 is on line 1 and Seed 2 on line 128, and the other seeds go onto fixed lines spread through the draw. Table tennis states the aim in words: the highest ranked entries are seeded "so that they cannot meet before the closing rounds". BMX racing says the same of its opening heats: the top ranked riders are kept from racing each other until the later phases.

Give the best the weakest opponent. The Olympic sprint pairs first against 24th, second against 23rd and so on. World Curling's quarter-finals for eight teams pair first against eighth, fourth against fifth, third against sixth and second against seventh. The knock-out final that the ski federation's rules provide for single-hit events such as big air uses the same ladder for 16: first against 16th, eighth against ninth, fifth against 12th and fourth against 13th in one half.

Spread strength evenly. Heats and groups should be about equal. Athletics deals the ranking out in a zigzag. Fencing lays its ranked fencers across the pools in a snake, and breaking does the same with groups of four. Roller speed skating composes its heats by what its rules call the serpentine system. Olympic badminton puts one seed at the top of each group. Rowing does the least: in principle two seeded crews per heat, the highest seed paired with the lowest.

Put the fastest last. Swimming seeds its heats so that the fastest swimmers are in the final heats, with the slower heats swum first.

Set the order of starting. At International Skating Union short track events, the starting order of each race follows the seeding. At ordinary international competitions it is drawn.

Seeds drawn in pairs

Between a fixed place and a free draw there is a halfway method: rank the entrants, then draw lots within small bands.

Fencing uses it for the 16 fencers exempted from the early rounds at its senior events. They take places 1 to 16 in the table "drawing lots in pairs" in the order of their ranking. In team events the first four teams are placed by ranking and the rest are drawn in pairs. Wheelchair fencing draws its whole table that way: 1 and 2, 3 and 4, 5 and 6.

Olympic water polo fills its two groups by pairs as well. The two best teams from the previous World Championship are drawn one into each group, then the next pair, and so on.

The effect is that the top seed and the second seed are treated as roughly equal, and neither can count on a particular position.

Seeding that changes during the event

A seed is not always fixed at the start.

In athletics, after the first round, heats up to 400 metres are built from the placings and times of the round just run. Short track does the same: for every round after the first, the seeding list puts skaters in order of their finishing positions and then their times in the round before. Surfers are seeded into each successive heat according to the position they took in the previous one.

Team tournaments can reseed at the join between groups and knockout. Para ice hockey ranks all its qualifiers afresh after the preliminary round.

Chess goes furthest. In a Swiss tournament the pairings are remade before every round from the current scores, so the event reseeds itself continuously.

Where chance stays in

Even a seeded draw leaves a lot to lots.

In a Grand Slam, only the top two seeds have a fixed line. Seeds 3 and 4 are drawn between two lines, seeds 5 to 8 among four, and everyone unseeded is drawn into what is left. Table tennis follows the same pattern in bands of 3 to 4, 5 to 8, 9 to 16 and 17 to 32. In athletics the lanes are drawn within ranking groups, and the order in which the heats are run is drawn too.

Lots also fill the gaps a ranking leaves. In fencing, fencers who are not in the ranking are placed by drawing lots. In short track, skaters with neither a ranking nor a submitted time are ranked by a draw.

Some sports lean much further towards chance. Wrestling pairs its bracket in the order of numbers drawn at random. Dragon boat racing divides crews into heats by lot unless their relative standards are known. BMX racing allows fully random seeding, and a "scrambled" method that sets the heats at random.

Chance has a cost, and one rule book says so. Where surfing heats have to be made by random draw, a repechage round is recommended after the first round.

Limits on who can meet

Rules often forbid a meeting outright. At Paris 2024, badminton players or pairs from the same National Olympic Committee could not be drawn in the same group. Athletics separates athletes of the same country, and the best performers, across the heats where possible. Roller speed skating does not put two skaters of one nation in the same qualification heat.

Table tennis has the fullest version. An association's first and second players go into different halves, and its third and fourth into the remaining quarters. Fencing separates compatriots in the pools and then drops the protection for the elimination table.

Surfing takes the other view. The International Surfing Association's rules say that heats which end up with athletes from the same country are not reseeded, and the draw is final.

There is a limit on seeding itself in team events. In a table tennis team knockout, only the highest ranked team from an association is eligible to be seeded.

Entry is not seeding

Two different questions are easy to run together: who gets into the draw, and where they are put.

A Grand Slam singles draw of 128 has 104, 108 or 112 direct acceptances by ranking, then 16, 12 or 8 qualifiers and 8 wild cards. A wild card is a place given at the tournament's own discretion. A qualifier won a place through the qualifying competition, and is drawn into the main draw. A lucky loser lost in qualifying and gets in because someone withdrew.

Wheelchair tennis draws the line most clearly. A player returning from at least six months out through a medical condition or pregnancy may be given a protected ranking, based on their ranking before they stopped. It can be used to enter a main draw or a qualifying draw. It "is not valid for Seeding purposes".

So a returning champion can be in the draw and unseeded, and can land next to the top seed in the first round.

When a seed withdraws

The draw is not simply left with a hole, and it is not quietly rearranged either.

Under the Grand Slam rules, if one of seeds 1 to 4 withdraws before the first day's order of play is released, the fifth seed moves into the open position, the 17th seed takes the fifth seed's place, and the next highest ranked player becomes a seed. If two or more of the top eight seeds withdraw more than 48 hours before the start, the tournament may remake the draw.

Table tennis says a player shall not be moved from one place in the draw to another. If the draw becomes seriously unbalanced, the event is, wherever possible, completely re-drawn. Where the imbalance comes from several seeds missing from one section, only the remaining seeds may be re-numbered and re-drawn among the seeded places.

Fencing leaves the gap. If one of its 16 exempted fencers does not appear, the position in the table stays empty and the fencer's federation is fined.

Rowing and tug of war both allow a new draw when withdrawals change the shape of the competition. Surfing does not: once the initial draw is made, there are no redraws for no-shows.

A draw is made in the open

The Grand Slam rules require the referee to make the singles draw publicly, at a time and place the tournament announces. At the Olympic badminton draw, each competing National Olympic Committee may be represented. In table tennis, representatives of every association with players in the event are entitled to attend the draw and must be consulted on any alteration that affects their players.

Rowing holds its draw at the team managers' meeting, with a member of the jury supervising. Tug of war makes its draw in the presence of the federation's delegates. Darts has a one-line rule: there shall be only one draw for opponents, made before the tournament.

Chess asks for something stronger than openness. Its pairing systems must be reproducible, so that different arbiters, or different approved programs, arrive at identical pairings from the same results.

What seeding is for, and what it costs

This section is reasoning, apart from the quotations.

Seeding protects the event. A final between the two best entrants is worth more to a tournament than the same match in the first round, and seeding makes it more likely. Rowing's rules put the same point defensively: seeding exists "to avoid many of the faster boats in an event being drawn into the same heat".

It also protects the seeds. A top seed gets byes, weaker early opponents and a later start. Those advantages help them keep the ranking that earned the seed. Sports that seed from a time trial at the event, or reseed from the previous round, soften this, because the advantage has to be earned again each time.

And it depends on the ranking being right. A strong entrant with no ranking, a newcomer or someone back from injury, is placed as if weak. The opponent who draws them pays for the error.

It changes from event to event

The one thing to remember: on any draw sheet, look for three things. Which entrants were placed and which were drawn? What ranking, of what date, did the placing use? And which meetings were ruled out before the draw began?