SSM - Swiss System Modified rules for pairing Manual method Currently in use by the AJSP Ver 20.01.04 A. Definitions A1. Scoring The game outcome score is calculated accordingly to the rules (GAM). Before the first game all players have 0 WDL score. If a game is ended on a time limit, the tournament regulations should clearly determine which game outcome will apply. WDL scoring: a) Win - 2 points b) Draw - 1 point c) Loss - 0 points Missing a game equals 0 points. A2. Ranking criteria Players are ranked accordingly to the following criteria, by decreasing priority order: a) WDL score - sum of score points during the tournament. b) SOS - the sum of the opponents scores. c) GAM score. d) Rating - optional. e) Random. A3. Score brackets Players with equal scores constitute a homogeneous score bracket. Any score bracket including players with different scores is heterogeneous. Players who remain unpaired after the pairing of a score bracket will be moved down to the next score bracket, which will therefore be heterogeneous. A4. Floats By pairing a heterogeneous score bracket, players with unequal scores will be paired. These players will receive a float remark. The higher ranked player will receive a downfloat, the lower one an upfloat. A5. Subgroups For pairing, each score bracket will be divided into two subgroups, designated as S1 and S2. S1 subgroup contains half the players from that score bracket, rounding down. S1 will innitially include the higher ranked players within that score bracket. S2 will contain half, or half plus 1, of the lowest ranked players in the score bracket. The number of players in S1 will be indicated by "p", indicating the maximum possible number of pairings that can be made within that score bracket. A6. Exchanges and transpositions Exchanges occur when players are swapped between S1 to S2. Transposed are those players that have to be moved from their initial score bracket. A7. Combinations A combination takes place when two or more score brackets are merged into a single heterogeneous score bracket. In this case any previous pairings of both score brackets are undone. A8. Byes Should the total number of players be or become odd during the tournament, one player ends up unpaired. This player receives a bye. A bye automatically awards 2 points and it is also considered to be a downfloat for that round (A4). B. Pairing Criteria Absolute Criteria (These may not be violated. If necessary players will be transposed to a contiguous score bracket.) B1. Two players can not meet more than once. B2. No player shall receive more than one bye. B3. There can not be more than one unpaired player per round. Relative Criteria (These are in descending priority. They should be fulfilled as much as possible, including exchanges, but can not force moving players to another score bracket). B4. Optional Restricted pairing In events that include the participation of small groups of players from other countries, cities, minoritary clubs or teams, players from each group may be prevented from being paired with each other for the number of rounds decided by the organization, with the exception of at least the last round. It this recommended that this rule is applied if each minoritary group includes a maximum of 20% of the tournament players. B5. No player should receive an identical float in two consecutive rounds. C. Pairing Procedures Starting with the highest score bracket apply the following steps: C1. Score brackets are formed. Whithin each score bracket players are ranked accordingly to A2 criteria. C2. Distribute the players among S1 and S2 subgroups. By default, players are also ranked in each subgroup. C3. The first S1 player is paired to the first S2 player, the second S1 to the second S2, etc. If a player cannot be paired respecting all B criteria, apply C4. If a p number of pairs is obtained, pairing within this score bracket is concluded. If any unpaired player remains, he is transposed to the next lower score bracket. If this is the last bracket, C9 is applied. C4. Each time a pair does not comply to all B conditions, another pair is attempted with the next S2 player, until all possibilities within S2 are exausted. If a pair cannot be found, apply C5. C5. Omit B5 criteria and pairing is attempted withing the complementary subgroup. If pairing is still not possible, then criteria B4 is ommited. If pairing is not possible apply C6. C6. Exchange the unpaired S1 player with the first free S2 player, rearranje the subgroups and apply again the C3 procedure. If pairing is still not possible adopt C7. C7. If a score bracket includes a player that cannot be pairing without violating B1 to B3, then that player is transposed to an inferior bracket, restarting from C2. If pairing is still not possible and the current number of players is odd, this player is given priority for a bye. If this violates B2 or B3, C8 is applied. If this is the last score bracket then go to C9. C8. All free players are transposed to the next inferior score bracket. Restart from C2. C9. If there is an odd number of players this player has priority for a bye. Otherwise all players within this score bracket are combined with the immediately superior score bracket. The procedure is then restarted from C2. D. Victory criteria In order to make the final standings the following criteria apply, in descending priority: a) WDL score - final WDL score points sum. b) SOS - the sum of all the opponent WDL scores. c) GAM points - sum of the GAM score for the player. d) Winner of the game played against each other - if the tie concerns the two players only.