Home

Welcome to the Ire wiki! Here we describe how the little computer program works, or at least how it is supposed to work.

Introduction

Ire allows you to make a draw for a McMahon Go tournament. It is intended for use with the European Go Rating (GoR) system, but it is not impossible to use it for another system. Dan or Kyu grades are not used to pair players. Ratings are used to pair players. The user interface is absolutely minimalist, we run off command line and text files. The pairing rules we support are based on FIDE's Swiss pairing rules. To help you understand how things work, we have the next section.

Vocabulary

• effective rating: A player in the top group, or with a rating below the rating floor, will have their rating changed for the purposes of the pairing, the effective rating is the value it will be changed to.
• grade width: (or rank width if you prefer) In GoR this is normally 100 points, and the value considered to be equal to 1 stone in strength. It is used in the assignment of MMS and the calculation of handicap stones.
• handicap adjustment: the number of stones to deduct from the default handicap. Normally a 1-dan playing a 2-kyu would be 2 stones. This value is listed as handicap policy in the Settings file.
• maximum handicap: In Europe, games over 9 handicap stones are not counted towards ratings. So by default this parameter is 9, but you can change it. Some programs suggest you add additional komi beyond 9 stones, but we regard this as a deviant practice.
• McMahon Score: Abbreviated to MMS, this is equal to your starting position plus the number of wins, plus half the number of draws and byes you have. The starting position is determined by your rating and the grade width.
• MDOS: A tiebreaker. I might have invented this one. It is the mean value of your SODOS.
• MOS: A tiebreaker. Taking a slight liberty, this is the Median Opponent's Score. The score from the highest and lowest opponent are dropped. In the case of byes, an average from actual opponents will be used. For a very short tournament, such as 3 rounds, this might be unhelpful. In chess it is called Median or Median-Buchholz. It is not SOS-2.
• rating bar: This is the rating above which all players, excepting those who have to take a bye, are placed in the top group.
• rating floor: The lowest rating to be allowed. If we choose to have a rating floor, then any player with a lower rating has their rating reset to the value of the rating floor.
• SODOS: A tiebreaker. This is the sum of your defeated opponents' MMS. In the case of byes, an average from actual opponents will be used. In chess it is called Sonneborn-Berger.
• SOS: A tiebreaker. This is the sum of your opponents' MMS. In the case of byes, an average from actual opponents will be used. In chess it is called Solkoff.
• top group: The group of players who should be able to win the tournament. All other players would start with a lower McMahon score. Normally players in the top group are forbidden from playing a handicap game, but you can change this setting.

Having read this, you can now read the outline page.