Skip to content

TOURNAMENT_LOGIC.md

Latest commit

 

History

History
67 lines (43 loc) · 3.2 KB

TOURNAMENT_LOGIC.md

File metadata and controls

67 lines (43 loc) · 3.2 KB

Tournament Logic Documentation

This document describes the scoring, advancement, and seeding logic used in the tournament system.

1. Swiss Phase (Group Phase)

The Swiss Phase is the initial part of the event where teams play a fixed number of rounds against opponents with similar records.

Scoring and Ranking

  • Primary Score (score): Teams receive 1 point for each match win.
  • Secondary Score (Buchholz Points): Used as a tie-breaker. A team's Buchholz points are calculated as the sum of the current scores of all opponents that the team has defeated.
    • Note: This is a modified Buchholz system that specifically rewards wins against stronger opponents.
  • Ranking Order: Teams are ranked by:
    1. score (Descending)
    2. buchholzPoints (Descending)

Round Generation

  • Number of Rounds: The maximum number of Swiss rounds is calculated as ceil(log2(N)), where N is the number of teams.
  • Pairing Algorithm: The system uses standard Swiss pairing, attempting to match teams with identical or similar scores while avoiding Repeat Matches (teams cannot play the same opponent twice in the Swiss phase).
  • Byes: If there is an odd number of teams, one team receives a "Bye" each round. A Bye counts as a win (1 point). No team can receive more than one Bye during the Swiss phase.

2. Transition to Elimination Phase

Once the maximum number of Swiss rounds is completed, the system determines which teams advance to the final tournament bracket.

Advancement Criteria

The system automatically advances the top teams based on the Swiss rankings. The number of teams selected is the highest power of two that is less than or equal to the total number of teams ($2^{\lfloor \log_2(N) \rfloor}$).

  • Example 1: If there are 12 teams, the top 8 teams advance.
  • Example 2: If there are 16 teams, all 16 teams advance.
  • Example 3: If there are 20 teams, the top 16 teams advance.

3. Elimination Phase (Tournament Phase)

The Elimination Phase is a single-elimination bracket.

Initial Layout (Seeding)

The initial matches (Round 0) are generated based on the final Swiss rankings (Seed 0 is the 1st ranked team, Seed 1 is the 2nd, etc.).

The seeding follows a "Snake" pairing logic to ensure high-seeded teams are distributed across the bracket and don't meet until later rounds. For $N$ advancing teams, the pairings are:

Match Pairing (Seeds) Sum of Seeds
Match 1 Seed 0 vs Seed $N-1$ $N-1$
Match 2 Seed 2 vs Seed $N-3$ $N-1$
Match 3 Seed 4 vs Seed $N-5$ $N-1$
... ... ...
Match $N/2$ Seed $N-2$ vs Seed 1 $N-1$

Example for 8 Teams:

  • Match 1: Seed 0 vs Seed 7 (1st vs 8th)
  • Match 2: Seed 2 vs Seed 5 (3rd vs 6th)
  • Match 3: Seed 4 vs Seed 3 (5th vs 4th)
  • Match 4: Seed 6 vs Seed 1 (7th vs 2nd)

Bracket Progression

The winners of Match 1 and Match 2 meet in the next round. The winners of Match 3 and Match 4 meet in the next round. This ensures that the 1st and 2nd seeds (Seed 0 and Seed 1) are in opposite halves of the bracket and can only meet in the final.