OlimpBase Help

1.5. Tie-breaking

The following tie-breaking methods are used to round-robin, Swiss and knock-out events:

  • Round-robin

    • Game points (board points) - sum of game points scored at respective boards. 1 game point for a game win, ½ game point for a game draw.

    • Match points - 2 match point for winning a match, 1 match point for drawing a match

    • Berger - For team events weighted Berger most commonly used. It is the sum of the scores of the opponents teams, each multiplied by the scores achieved against this opponent team. Alternatively unweighted Berger might be of use, where only match result matters, thus ignoring the margin of a win.
      Example: team A defeated team B (finished at 12.5 points) by 3½-½, drew with team C (finished at 16 points) by 2-2 and lost to team D (finished at 21.5 points) by 1-3.
      Weighted Berger = 12.5*3.5 + 16*2 + 21.5*1 = 97.25
      Unweighted Berger = 12.5*1 + 16*0.5 + 21.5*0 = 20.50

    • ...

  • Swiss system

    • Buchholz

    • Progress - is quite uncommon these days but is still in use (see e.g. Blind Olympiads). Progress is a sum of sums of points at the end of each day.
      Example: a team scored the following in a 5 round Swiss: 4-0, 3-1, 1-3, 1½-2½, 2-2.
      Team's total score at the end of respective rounds will be: 4.0, 7.0, 8.0, 9.5, 11.5
      Team's progress at the end of each day will be: 4, 4+7=11, 4+7+8=19, 4+7+8+9.5=28.5, 4+7+8+9.5+11.5=39 Team's progress at the end will be 39.0.

  • Knock-out

    • Board count - Note down the numbers of the boards each team won on, and add up those numbers for each team. The team with the lowest total is deemed to be the winner. If board count fails to produce a winner, use the elimination rule.
    • Elimination rule - Eliminate the bottom board, and add up the points scores for the remaining boards of each team. If the scores are still level, eliminate the next board etc until the tie is broken. The team with the highest score is deemed to be the winner.
    • Crepaux system - when there is odd number of teams the Crepaux system saves one day as there are no byes. There are teams A, B, C, each one of four players. Under classical round robin the tournament takes three rounds to complete, under Crepaux system pairing is e.g. as follows:
      Round 1: A1-B1, A2-B2, B3-C1, B4-C2, C3-A3, C4-A4
      Round 2: A3-B3, A4-B4, C1-B1, C2-B2, C3-A1, C4-A2
      There are 2 rounds and not 3 but still 12 games are played, and each team played the other one on four boards, just like in the classical round robin.

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