Seed (sports)

A seed is a preliminary ranking that can be used in arranging a sports tournament. It is called a seed because of the analogy with plants where the seed might grow into a top rank at the end of that tournament, or might instead wither away. Players/teams are 'planted' into the bracket in a manner that is typically intended so that the best don't meet until later in the competition.

One version of seeding is where brackets are set up so that the quarterfinal pairings (barring any upsets) would be the 1 seed vs. the 8 seed, 2 vs. 7, 3 vs. 6 and 4 vs. 5; however, this is not the procedure that is followed in most tennis tournaments, where the 1 and 2 seeds are placed in separate brackets, but then the 3 and 4 seeds are assigned to their brackets randomly, and so too are seeds 5 through 8, and so on. This may result in some brackets consisting of stronger players than other brackets, and since only the top 32 players are seeded at all in Tennis Grand Slam tournaments, it is conceivable that the 33rd-best player in a 128-player field could end up playing the top seed in the first round. Rankings of tennis players are generated by computers, and players tend to change ranking positions gradually, so that a more equitable method of determining the pairings might result in many of the same head-to-head matchups being repeated over and over again in successive tournaments.

Sometimes the remaining competitors in a single-elimination tournament will be "re-seeded" so that the highest surviving seed is made to play the lowest surviving seed in the next round, the second-highest plays the second-lowest, etc. This may be done after each round, or only at selected intervals. In American team sports, for example, both the NFL and NHL employ this tactic, but the NBA does not (and neither does the NCAA). MLB does not have enough teams in its playoff tournament where re-seeding would make a difference in the matchups. (The NFL is at the minimum, which is 6 from each league [or conference in the NFL, NBA or NHL] for a total of 12.) The NBA's format calls for the winner of the first-round series between the first and eighth seeds (within each of the two conferences the league has) to face the winner of the first-round series between the fourth and fifth seeds in the next round, even if one or more of the top three seeds had been upset in their first-round series; critics have claimed that this gives a team fighting for the fifth and sixth seeding positions near the end of the regular season an incentive to tank (deliberately lose) games, so as to finish sixth and thus avoid a possible matchup with the top seed until one round later.

In some situations, a seeding restriction will be implemented; from 1975 until 1989, the National Football League and, since seeding began in 1998, MLB have a rule where at the conference or league semifinal, should the top seed and last seed (wild card) be from the same division, they may not play each other;  in that case, the top seed plays the worst division champion;  the second-best division champion plays the wild card team.