The basic idea
In double elimination a team is out only after two losses. Every team starts in the upper bracket, which runs like a single elimination knockout. A team that loses there drops into the lower bracket, where one more loss ends its event. The upper bracket winner and the lower bracket winner meet in the grand final.
The main benefit is protection against a bad game. In a plain knockout, one upset can eliminate the best team; here, a strong team that stumbles can still recover. That makes the final result somewhat more reliable, although not perfectly so.
How many matches
For n teams, double elimination needs 2n - 2 matches if the grand final is a single match, and 2n - 1 if a reset is played. With eight teams that is 14 or 15 matches, compared with 7 for single elimination. In other words, the format roughly doubles the schedule, which is the price of the second chance.
Round robin for eight teams needs 28, so double elimination sits between the two in cost, and it keeps the drama of knockout play.
The grand final and the reset
The two finalists have different histories. The upper bracket winner has no losses, while the lower bracket winner has one. If both finalists were treated equally, the lower bracket team could win one match and take the title having lost twice in total, whereas the upper bracket team would be out after its first loss. That seems unfair to a team that was unbeaten.
Many events solve this with a bracket reset. The upper bracket winner starts the grand final with a life in hand. If the lower bracket team wins the first grand final match, both teams now have exactly one loss, so a second match decides the title. If the upper bracket team wins the first match, the event ends. This is why the total is sometimes 2n - 1 matches.
Some organisers skip the reset and play a single grand final to keep the schedule tight. This gives the lower bracket finalist a harder task but is not universal, so the rule is worth checking before reading anything into a result.
Odd imbalances
Double elimination looks symmetrical, but it is not.
Uneven rest. The lower bracket champion usually plays many more matches than the upper bracket champion. Having already played several matches in a row, the lower bracket finalist may be more tired, while the upper bracket finalist has had more rest. On the other hand, the lower bracket team may be warmed up, and some players find extra games helpful. The effect is not consistent and depends on the game and the schedule.
Different opponents. A team dropping from the upper bracket meets lower bracket opponents who have already won a match or two, so the route can be harder than the initial seeding suggests. Seeding in double elimination therefore shapes not only the first rounds but also the drop-down path.
Repeat matches. Because teams drop and re-enter, two teams may meet twice. That brings an adaptation effect: the second meeting follows a game where each side has seen the other’s preparation. Rematches can be won by the side that learns faster, rather than the side that is stronger overall. In drafted games, the pick and ban choices from the first meeting are known to both sides.
Early elimination quirk. Some drop-down placements pit teams from the same upper bracket match against each other again soon after, depending on how the lower bracket is wired. Many events adjust the wiring to avoid rematches in the first lower bracket round.
Does it reward the best team?
Compared with single elimination, usually yes. A stronger team needs to lose twice to be removed, so the chance of an early exit through one upset drops. The benefit is largest when single games are noisy, so a format using best of one games gains the most from the second chance.
The format does not remove luck. A team with a hard route can still lose twice, and a team that simply benefits from a favourable bracket can profit. There is also a subtler point: a team that loses in the upper bracket and wins its way through the lower bracket demonstrates resilience, but only after beating a series of opponents who may be weaker than the ones in the upper bracket.
When it fits
Double elimination suits events where organisers want a knockout feel, a stronger guarantee against flukes, and a moderate match count. It is less suitable when time is short, since the schedule is long and the lower bracket can run late into the night.
For a ranking of all teams rather than a single winner, a round robin or Swiss structure usually gives a cleaner picture, because every team plays several opponents regardless of early results.