Sonneborn-Berger (Neustadtl Score)
Add the scores of every opponent the player beats and half of the score of every opponent the player draws (Just & Burg 2003:201). The system was named after William Sonneborn and Johann Berger, but it was invented by Oscar Gelbfuhs (Harkness 1967:137). The system is the main tie-breaking system in round robin tournaments, but is also used in Swiss tournaments. It is also called the Neustadtl score.
Read more about this topic: Tie-breaking In Swiss-system Tournaments