Competition structures
Parful runs thisDouble elimination
Also called Double-elimination bracket, Losers bracket, Second-chance bracket, Winners and losers bracket.
Double elimination is a bracket in which a player is out only after two defeats. A first loss drops the player into a losers bracket that runs alongside the winners bracket; the two champions meet in a grand final, and if the losers champion wins it the bracket resets for one deciding match.
- Eliminated after
- 2 defeats
- Field
- 4, 8 or 16 players, one bracket, no flights or byes
- Losers bracket rounds
- 2 for a 4 draw, 4 for an 8 draw, 6 for a 16 draw
- Grand final
- Winners champion v losers champion
- Bracket reset
- A second grand final if the losers champion wins the first
- Third place
- The loser of the losers final
How double elimination works
A single elimination knockout gives every player one bad day to end their tournament. Double elimination gives a second one. The winners bracket is an ordinary seeded knockout. Anyone who loses in it drops into the losers bracket, where a second defeat is final. The winners bracket champion has lost nothing; the losers bracket champion has lost exactly once. They meet in the grand final.
Because the winners champion is unbeaten, the losers champion has to beat them twice. Winning the first grand final levels the count at one loss each and triggers the bracket reset, a single deciding match. If the winners champion wins the first grand final it is over.
The losers bracket, round by round
For a winners bracket of N players the losers bracket has 2 x log2(N) minus 2 rounds and alternates between two kinds. A major round pairs each surviving losers-bracket player against a fresh drop from the winners bracket, one to one. A minor round pairs the survivors with each other and halves the field. The pattern is: round 1 pairs the winners round 1 losers, round 2 brings in the winners quarter-final losers, round 3 pairs the survivors, round 4 brings in the semi-final losers, and so on until the losers final, which takes the loser of the winners final.
The first losers round swaps halves: losers from the top half of the winners bracket meet in the bottom half of the losers bracket and vice versa, so a player does not immediately replay the opponent who just beat them. Later rounds pair sequentially.
- 4 players: winners 3 matches, losers 2 rounds of 1 match, grand final, possible reset. 7 or 8 matches in all.
- 8 players: winners 7 matches, losers rounds of 2, 2, 1 and 1 matches, grand final, possible reset. 14 or 15 matches.
- 16 players: winners 15 matches, losers rounds of 4, 4, 2, 2, 1 and 1 matches, grand final, possible reset. 30 or 31 matches.
Placings
The grand final decides first and second. Third place is the loser of the losers final, the last player eliminated before the grand final, so no separate third-place match is needed or offered. The loser of the losers round before that is fourth.
How Parful runs it
Double elimination is a switch on a club knockout competition. The winners bracket generates from the field with the usual seeding, then the losers bracket, grand final and reset are attached below it. Every winners bracket match knows which losers bracket slot its loser drops into, so when a result is recorded the loser is moved automatically and the winner advances as normal. The reset match sits greyed out as conditional until the losers champion wins the first grand final.
Parful runs double elimination on one unflighted bracket with a power-of-two field of 4, 8 or 16 players, with no byes and no flights. A qualifier round can sit in front of the winners bracket, but qualifier losers do not enter the losers bracket. The bracket locks once any match has a result, and walkovers, concessions and voids work as they do in a single elimination bracket.
Worked example
A worked example: 8 players
Eight players seeded by Course Handicap™. The winners bracket runs 1 v 8, 4 v 5, 2 v 7, 3 v 6. The table shows every losers bracket match, where its two players come from, and where the winner goes.
| Round | Match | Side A comes from | Side B comes from | Winner goes to |
|---|---|---|---|---|
| Losers round 1 | LB1 M1 | Loser of WB match 3 (2 v 7) | Loser of WB match 4 (3 v 6) | LB2 M1 |
| Losers round 1 | LB1 M2 | Loser of WB match 1 (1 v 8) | Loser of WB match 2 (4 v 5) | LB2 M2 |
| Losers round 2 | LB2 M1 | Winner of LB1 M1 | Loser of WB semi-final 1 | LB3 M1 |
| Losers round 2 | LB2 M2 | Winner of LB1 M2 | Loser of WB semi-final 2 | LB3 M1 |
| Losers round 3 | LB3 M1 | Winner of LB2 M1 | Winner of LB2 M2 | Losers final |
| Losers final | LB4 M1 | Winner of LB3 M1 | Loser of WB final | Grand final |
| Grand final | GF | Winners bracket champion | Losers bracket champion | Reset if the losers champion wins |
| Reset | GF2 | Same two players | Same two players | Champion |
- Suppose Ana (seed 1) wins the winners bracket unbeaten and Cal (seed 3) comes through the losers bracket after losing to Ana in the semi-final. Cal must beat Ana twice; Ana must beat Cal once.
- The loser of LB4 M1 is third. Nobody plays a third-place match in double elimination.
Common variants
- No bracket reset
- Some events play one grand final only, giving the losers champion no second bite. Parful always offers the reset; the admin can leave it unplayed and record the first grand final as the result.
- Full cross-drop
- A drop pattern arranged so nobody can replay a previous opponent anywhere in the losers bracket. Parful swaps halves in losers round 1 and drops sequentially after that, which avoids an immediate rematch but not every later one.
- Flighted double elimination
- A separate double elimination per flight. Parful runs double elimination on one unflighted bracket only.