The Sonneborn-Berger tiebreak is a scoring system used in chess tournaments to break ties among players with the same number of points at the end of the event. It is named after its two inventors, William Sonneborn and Friedrich Berger.

Explanation:
In chess tournaments, players earn points based on their performance in games (e.g., 1 point for a win, 0.5 points for a draw, and 0 points for a loss). When the tournament concludes, some players may have accumulated the same number of points, leading to a tie for their final ranking.

To resolve the tie and determine the final standings, the Sonneborn-Berger tie break comes into play. It calculates the performance of each player’s opponents and rewards players who have defeated strong opponents.

Here’s how the Sonneborn-Berger tiebreak is calculated:

1. For each player, sum up the total points earned by all the opponents they defeated during the tournament.
2. For each player, if they had any draws, sum up half of the total points earned by all the opponents they drew against.
3. The player with the highest sum of points from the above calculations gets a higher Sonneborn-Berger score.
4. If there is still a tie after applying the Sonneborn-Berger tiebreak, other tiebreak methods like the Buchholz tiebreak or the performance rating may be used.

In simple terms, the Sonneborn-Berger tiebreak rewards players for their draws against strong opponents as well as their own victories. Defeating a player who performed well in the tournament becomes more valuable, making it a crucial factor in determining the final rankings in chess competitions with tie situations. The Sonneborn-Berger tiebreak is widely used in chess tournaments to ensure a fair and decisive outcome when players finish with the same number of points.

The Swiss System is a widely used pairing method in chess tournaments, designed to efficiently match players of similar strength against each other without elimination. It allows players to compete in multiple rounds, ensuring a fair and competitive environment throughout the event.

Explanation:
In chess tournaments that use the Swiss System, participants are paired against opponents based on their current score and performance. The goal is to match players who have similar results to create balanced and competitive matchups in each round. Unlike elimination formats, where players are knocked out after each round, the Swiss System allows all participants to play in every round regardless of their performance.

Here’s how the Swiss System pairing process typically works:

1. Initial Pairing: In the first round, players are usually paired randomly or according to some predetermined criteria, like in order of rating followed by alphabetical order of the players’ names.
2. Scoring: After each round, players are awarded points based on their results (e.g., 1 point for a win, 0.5 points for a draw, and 0 points for a loss).
3. Pairing in Subsequent Rounds: For the following rounds, the pairing system aims to match players with the same or similar scores, ensuring that players with similar performance levels face each other. It avoids pairing players who have already played against each other and ensures that no player uses the same colour in more than two consecutive games.
4. Number of Rounds: The number of rounds in a Swiss System tournament may vary, depending on the organizers and the number of participants. The more rounds there are, the more reliable the final standings are likely to be.
5. Final Standings: After all the rounds are completed, the players’ final standings are determined based on their total points accumulated throughout the tournament. Tiebreakers like the Buchholz, Sonneborn-Berger, or Number of Victories may be used to break ties if necessary.

In summary, the Swiss System of pairings in chess allows players to compete in multiple rounds while ensuring that opponents are of similar strength. It provides a fair and balanced competition, and it is commonly used in chess tournaments of various sizes and levels to determine the overall winner and final standings.