Pairing Algorithm
The AccelRat pairing algorithm is designed to pair round by round, that is, all the players are paired, the games are played and results reported, and then the next round is paired.
The pairing algorithm starts with seed ratings for all the players, and records of all the games that have been paired in previous rounds.
The ratings of all the players are updated before pairing. Because updated ratings take into account both seed ratings and win-loss records in a logically correct way, the pairing algorithm can simply look at the updated ratings, and does need to consider seed ratings and win-loss records separately.
If ratings were not updated between rounds, then underrated players would usually win most of their games, and overrated players would lose. Players are better matched using updated ratings.
If there are an odd number of players, a bye is assigned. You should find one or more volunteers ahead of time, and mark them in your tournament register. The pairing algorithm will rotate the odd-number-of-players bye among the players you designate.
Players are paired in rating order, starting at the top. This means that the stronger players have the privilege of selecting the best available opponent, and weaker players have to choose between those who remain unpaired. Opponent selection involves several constraints and quantitative criteria.
After players have been paired, handicaps are assigned to satisfy a target difficulty criterion which varies continuously with the ratings of the players. The effect is that games between dan level players get even game komi, and games between weaker kyu level players get handicaps, which most go players find reasonable.
In games with even game komi, colors are assigned to balance the number of times each player has held White and Black.