The Sonneborn-Berger tie-break, step by step
The Sonneborn-Berger tie-break rewards points scored against strong opponents: a win counts the beaten opponent’s whole score, a draw half of it. ChessLivo computes Sonneborn-Berger by the FIDE tie-break regulations (C.07) after every round, in round robins and in Swiss tournaments.
What is Sonneborn-Berger?
For each game, multiply the opponent’s final score by the player’s own score in that game, then add it all up:
- a win counts the opponent’s whole score;
- a draw counts half of it;
- a loss counts nothing.
Two players on equal points are separated by whom they took their points from: beating the leaders is worth more than beating the bottom of the table.
A worked example
The same six players as on the Buchholz page, after three Swiss rounds, computed by the same tie-break code as ChessLivo’s standings. A and F both have 2.5 points.
- A: 0 (D, won) + 2.5 × ½ (F, drawn) + 1.5 (E, won) = 2.75
- F: 1 (C, won) + 2.5 × ½ (A, drawn) + 1.5 (B, won) = 3.75
F’s wins came against opponents with more points, so F ranks ahead on Sonneborn-Berger too.
| Rk | Player | 1 | 2 | 3 | Pts | BH-C1 | BH | SB |
|---|---|---|---|---|---|---|---|---|
| 1 | F | C Black 1 | A White ½ | B White 1 | 2.5 | 4 | 5 | 3.75 |
| 2 | A | D White 1 | F Black ½ | E White 1 | 2.5 | 4 | 4 | 2.75 |
| 3 | E | B Black ½ | C White 1 | A Black 0 | 1.5 | 4 | 5 | 1.75 |
| 4 | B | E White ½ | D White 1 | F Black 0 | 1.5 | 4 | 4 | 0.75 |
| 5 | C | F White 0 | E Black 0 | D White 1 | 1 | 4 | 4 | 0 |
| 6 | D | A Black 0 | B Black 0 | C Black 0 | 0 | 4 | 5 | 0 |
Columns 1–3 are the rounds: the opponent, the colour (○ White, ● Black) and the score of that game.
Sonneborn-Berger in round robin and Swiss events
- Round robin. Everyone plays the same opponents, so Buchholz separates nobody and Sonneborn-Berger is the classic tie-break. ChessLivo’s default order for a round robin is direct encounter, Sonneborn-Berger, the number of wins and Koya.
- Swiss. Sonneborn-Berger usually comes after Buchholz: ChessLivo’s default order for a Swiss is Buchholz Cut 1, Buchholz, Sonneborn-Berger, direct encounter and the number of wins.
You choose your own list and order when you set up the tournament; publish it with your tournament rules.
Byes and forfeits
A round without a real opponent, such as a bye or a forfeit, has no opponent score to multiply. FIDE C.07 sets how such rounds count in Sonneborn-Berger, and ChessLivo applies those rules.
How to set the tie-breaks of a round robin: the round robin guide.
Sonneborn-Berger questions
- How is Sonneborn-Berger calculated?
- Add the final scores of the opponents the player beat and half the final scores of those they drew with; losses add nothing. In the example on this page, F’s Sonneborn-Berger is 3.75 and A’s is 2.75.
- What is the difference between Buchholz and Sonneborn-Berger?
- Buchholz adds up the scores of all the opponents, whatever the result. Sonneborn-Berger counts an opponent’s score only for the points taken from them: all of it for a win, half for a draw.
- Why is Sonneborn-Berger used in round robins?
- In a round robin everyone meets the same opponents, so players tied on points have opponents who scored the same total, and Buchholz separates nobody among them. Sonneborn-Berger still separates players, by whom they beat and drew with.
- What if Sonneborn-Berger is equal too?
- The next tie-break in the tournament’s list decides, for example the number of wins or Koya in a round robin. If every tie-break is equal, the players share the place unless the tournament rules say otherwise.
Standings with Sonneborn-Berger after every round
Run your round robin or Swiss on ChessLivo: enter the results and the standings, with Sonneborn-Berger and the other FIDE tie-breaks, follow by themselves.