Fill in the cross-table of a round-robin and the points, the Sonneborn-Berger score and the final placings are worked out for you. Below the table the calculator shows how each score was built up: who the player beat, who they drew with and what it adds up to. Nothing to install, everything runs in your browser.
Type the names and mark the results in the cross-table: clicking a cell cycles through 1 (win), ½ (draw), 0 (loss) and empty. The mirror cell fills in automatically, so the table can never contradict itself.
| Player | 1 | 2 | 3 | 4 | 5 | 6 | Points |
|---|---|---|---|---|---|---|---|
| 1 | × | 4 | |||||
| 2 | × | 2½ | |||||
| 3 | × | 2½ | |||||
| 4 | × | 2½ | |||||
| 5 | × | 2 | |||||
| 6 | × | 1½ |
Places are decided by points, and within equal points by the Sonneborn-Berger score.
| Place | Player | Points | SB score |
|---|---|---|---|
| 1 | Paul Grigoriev | 4 | 9 |
| 2 | Oleg Tarasov | 2½ | 6½ |
| 3 | Daria Belova | 2½ | 5¼ |
| 4 | Nikita Orlov | 2½ | 4¾ |
| 5 | Maria Savelieva | 2 | 4 |
| 6 | Ivan Krylov | 1½ | 4½ |
Rows are highlighted where several players share the same number of points: that is exactly where the score decides who finishes higher.
Wins over: Daria Belova (2½), Nikita Orlov (2½), Maria Savelieva (2) → 7
Draws with: Oleg Tarasov (2½), Ivan Krylov (1½) → half of 4 = 2
7 + ½ × 4= 9Wins over: Daria Belova (2½) → 2½
Draws with: Paul Grigoriev (4), Nikita Orlov (2½), Ivan Krylov (1½) → half of 8 = 4
2½ + ½ × 8= 6½Wins over: Nikita Orlov (2½), Maria Savelieva (2) → 4½
Draws with: Ivan Krylov (1½) → half of 1½ = ¾
4½ + ½ × 1½= 5¼Wins over: Maria Savelieva (2), Ivan Krylov (1½) → 3½
Draws with: Oleg Tarasov (2½) → half of 2½ = 1¼
3½ + ½ × 2½= 4¾Wins over: Oleg Tarasov (2½), Ivan Krylov (1½) → 4
4 + ½ × 0= 4Draws with: Paul Grigoriev (4), Oleg Tarasov (2½), Daria Belova (2½) → half of 9 = 4½
0 + ½ × 9= 4½SB = Σ scores of players you beat + ½ × Σ scores of players you drew with
The idea is that not every point costs the same. A win over the leader who finished on a big score weighs more than a win over the tail-ender, and a draw with a strong opponent brings in half of their total. Games the player lost do not enter the sum at all.
So between two players level on points, the one who earned them in the hard games finishes higher. In the demo tournament loaded by the “Load example” button, second place goes to a player with a single win: three draws against strong opponents produced a higher score than two wins each did for their rivals.
The score is only ever compared inside a group of players on equal points. A large Sonneborn-Berger number on its own wins nothing: a player with fewer points stays below, however impressive their tie-break looks.
Use the plus and minus buttons or type straight into the field. The calculator covers tournaments from three to twelve players, the usual size of a club or home round-robin.
Names are carried into the breakdown below the table, so you can see exactly who each half point came from. Leaving the default labels works too.
Clicking a cell cycles through win, draw, loss and empty. The mirror cell is filled in automatically, so recording “both players won” is technically impossible.
Points, the Sonneborn-Berger score and the places are recalculated on every click. Rows where several players hold the same number of points are highlighted, because that is where the score actually decides the placing.
Under the table the calculator shows how each score was built up: who the player beat, who they drew with and what the totals came to. That is what you show a player who asks why they finished second.
This happens in small events, where there are few possible values and they repeat easily. Then you go down the list of tie-breaks in your regulations. For round-robin events the usual order is: the result of the direct encounter between the tied players, then Sonneborn-Berger, then the Koya system - the points scored against opponents who finished on 50 percent or better.
The organizer rule that matters: fix the order of tie-breaks in the regulations before round one. An argument about who finished higher is settled by the published regulations, never by a discussion after the closing ceremony. If your event runs on the Swiss system instead, the standard tie-break there is Buchholz, and the walkthrough for setting up an event from scratch is in the guide to organizing a chess tournament.
Related reading: how many rounds a Swiss needs, the organizer guide and the tournament FAQ.
A calculator is what you want when the tournament is already played and you have the completed cross-table in front of you. If the event is still ahead, it is easier to run it in the Vibe Chess app: pick the round-robin format, add the players including guests without Telegram, and the round schedule is built from the field automatically. Results go in with a button press after each game, the table updates as you go, and the finished event exports as a TRF report.
Sonneborn-Berger = the sum of the final scores of all the opponents the player beat, plus half the sum of the scores of those the player drew with. The scores of opponents the player lost to are not included. That is the wording of the FIDE tie-break regulations.
Yes. The full name is Sonneborn-Berger, after Wilhelm Sonneborn and Johann Berger; in English-language software it is usually abbreviated to SB, and in Russian tournament practice it is normally shortened the other way round, to the Berger coefficient. There is no difference in the formula.
There is no point: the tie-break is built on the opponents' final scores, and those change right up to the last round. An interim figure tells you nothing.
Because the tie-break weighs whom you took your points off. Three draws with the leaders can be worth more than two wins over the tail of the table - that is exactly the point of the measure.
It will calculate the number, but in a Swiss the main tie-break is Buchholz. Sonneborn-Berger is used there only as a later criterion, and only if the regulations say so.
As an ordinary win: under the FIDE regulations, wins because the opponent did not appear go into the sum on the same footing as played games.
Move on to the next tie-break in the regulations: the direct encounter, the number of wins or the Koya system. Announce the order before round one.
No. Everything is calculated in your browser and nothing is sent anywhere. Closing the page clears the table.
Yes. Enter both games between each pair; the formula does not change - the opponents' final scores are simply higher.