Tiebreak System

The majority of tournaments held by Sydney Academy of Chess are run as Swiss tournaments.
A Swiss tournament pairs players so that everyone plays in every round.  A player scores one point for a win, half a point for a draw and no points for a loss.  Each round, players will be paired with someone on approximately the same score as themselves, and no one plays the same person twice within a tournament.

In the event of two players finishing the tournament on the same score, we still assign them places. We use the following tiebreaks to determine who places higher. The order that we use these tiebreaks is: M-Buch, Buch then Progr.  As such, Buch is only considered if M-Buch is equal, and Progr is only considered if both M-Buch and Buch are equal.

Buchholz (Buch.)

This is the sum of opponents' scores. The idea is that the same score is more valuable if achieved against players with a better performances in a given tournament.  It seems like an ideal tie-breaking method and has been used since the Swiss system was invented.  However it has some weaknesses, that are addressed by other methods such as Median-Buchholz.


Median-Buchholz (M-Buch.)

Same as above but discarding the highest and the lowest opposition's scores.

Its idea is to eliminate distortions in Buchholz values, caused by taking into account games against run-away winners and bottom placed players.

Progress (Progr)

Calculated by adding points from the end of each round. eg if your scores were: Win, Loss, Win, Draw then your progressive scores are 1, 1, 2, 2.5 and your Progress tie-break value is 6.5 (1+1+2+2.5)

This is an attempt to put a higher value on scores which were achieved by scoring better in the initial rounds than by finishing from behind.  It is common knowledge that the latter is usually much easier to achieve.

 

Round Robins

In the rare event that we run a round robin, the above tiebreaks are not suitable. We instead use the following two tiebreaks.
 

Berger (Berg.)

This is calculated by adding the score of each of your opponents multiplied by the score you achieved against that opponent. ie – adding the score * 1 for each opponent you beat, and the score *½ for each opponent you drew with.  Any opponent you lost to is ignored.
 

Number of Wins

Calculated by adding one point per win and nothing for a loss or draw.