Sonneborn-Berger Score Explained

A round-robin ends, two players are tied on points, and the standings put one above the other using something called the "Sonneborn-Berger score." The name is a mouthful, but the idea behind it is friendly: you get more credit for beating and drawing the players who did well than for scraping past the players who finished bottom. This guide walks through exactly how that number is worked out, using one small all-play-all tournament you can follow the whole way through. No maths degree required.

What Sonneborn-Berger Actually Measures

Here is the one sentence version. Your Sonneborn-Berger score is the sum of the final scores of the opponents you beat, plus half the final scores of the opponents you drew. Opponents you lost to add nothing. That is the whole rule.

Notice what makes it different from a plain opponent count: it cares about your result against each person, not just who you played. Beating a player who finished top of the table is worth a lot. Beating a player who finished last is worth almost nothing. A draw is worth exactly half of a win. So Sonneborn-Berger, often shortened to SB in standings, rewards the player who got their best results against the strongest opposition.

Let's Work Through a Real Example

Imagine a small six-player round-robin, so everyone plays everyone once. Two friends, Maya and Leo, both finish on 3.5 points. There is one trophy. Sonneborn-Berger will decide who lifts it.

To find Maya's SB, we go game by game. For every opponent, we note their final score and what Maya did against them: a win means we add the full score, a draw means we add half, a loss means we add nothing.

Now we do the exact same thing for Leo. Same tournament, same 3.5 points, but Leo's wins came against weaker finishers.

Maya's 9.5 beats Leo's 7.0, so Maya takes the trophy. Both scored 3.5 points, but Maya won her games against players near the top of the table, while Leo picked up his wins against the tail. Sonneborn-Berger measures exactly that difference. You just did it by hand.

Where the Numbers Come From

The part that trips people up is the same as with most tiebreaks: you use each opponent's final score, the total they finished the whole tournament on, not the score they had on the day you played them. An opponent you beat early who then goes on a run will lift your SB, because it turns out you beat someone strong. That is the point of the system.

It also means Sonneborn-Berger is not settled until the last game of the last round is done. Standings can shuffle right at the end as opponents finish their games, which is completely normal and not a bug.

Sonneborn-Berger vs Buchholz: Which Goes Where

These two get mixed up constantly because both reward a tough schedule. The difference is simple once you see it side by side.

Question	Buchholz	Sonneborn-Berger
What it adds up	Every opponent's final score	Opponents' scores weighted by your result
Does your result matter?	No, win or lose it counts the same	Yes: full for a win, half for a draw, none for a loss
Usual home	Swiss events	Round-robins (all-play-all)

The short version: Buchholz is the standard tiebreak for Swiss tournaments, and Sonneborn-Berger is the standard for round-robins. In a round-robin everyone plays the same field, so the only thing that separates two tied players is who they beat, and that is precisely what Sonneborn-Berger measures. If you want the full walk-through of the Swiss tiebreak, see our Buchholz system explained guide, or the wider chess tiebreak systems overview for the complete picture.

A Few Names That Cause Confusion

• SB: just the abbreviation for Sonneborn-Berger you will see in a results table, sometimes shown as a "TB" (tiebreak) column.
• Neustadtl score: the same calculation. It was described by Neustadtl before Sonneborn and Berger popularised it, so some rulebooks credit him. Same maths, different name.
• Berger tables: a completely different thing that happens to share the name. Berger tables are the round-by-round pairing charts for a round-robin, telling you who plays whom so everyone meets once. The tables set the schedule, the SB score breaks the ties.

The One-Minute Recap

• Sonneborn-Berger adds up full points for wins and half points for draws, using each opponent's final score.
• Losses add nothing, so it rewards good results against strong players.
• Higher SB wins the tie.
• You use each opponent's end-of-tournament total, not their score on the day.
• It is the standard tiebreak for round-robins, where Buchholz would treat every player the same.