Ladder tournament by groups – technical description

This document is a reference document for those of you who want to know how your new rank came about. If you cursor over your rank and click on “view” you will see the details of the calculations. You can do that with other players as well. Your comments and suggestions are welcome.

The main purpose of this tournament is to allow players to enjoy the game and play with others of the same skill level.

This particular tournament has over 80 players enrolled. Players have to sign up to play each week as only a limited number of courts are available.

In this case, 8 courts are available and 2 time slots.

There are 4 players per court allowing for 64 players. Each player pairs up with one of the other 3 in rotation. The match is over when all 3 games have been played and the score for the event is the total of the scores each player has received over the 3 games. In this case games are to 15, maximum score is 45.

New rankings are calculated on the basis of previous rankings and scores. These are subject to fine tuning change.

  1. set @winner = 1; #overall top player
  2. set @win = -4; #winner of each group
  3. set @lose = 2.4; #loser of each group
  4. set @lastlose = 3.4; #overall bottom player
  5. set @mid2nd = -.8; #players who comes in 2nd in their group
  6. set @mid3rd = 1.3; #players who comes in 3rd in their group
  7. set @noshow = 1; #players who did not play
  8. set @subst = 0; #substitute players

The above has been copied from the computer program which calculates the new rankings. These are explained below:

set @winner = 1; #overall top player

This is the automatic rank assigned to the player with the top score from group 1. This is the only rank that is independent of the previous ranking of a player.

All the following numbers represent numbers which are added to the player’s previous rank. These become calculated ranks and only serve to put the players in order, from lowest calculated rank to highest calculated rank. Ties are resolved by placing the player with the lowest previous rank first.

Thus,

the winner of each group gets -4 added to their previous rank. This becomes a calculated rank and must not be below 2 (1 is already allocated);

the player in 4th position in the last group gets +3 added to their previous rank (their ranking worsens);

the player in 4th position in each group gets +3 added to their previous rank (their ranking worsens);

the player in 2nd position gets -2 added to their previous rank (their ranking improves);

the player in 3rd position gets +1 added to their previous rank (their ranking worsens);

players who do not play in a particular session get +1 added to their previous rank (their ranking worsens). This prevents players choosing not to play to protect their ranking.

Players who are spares or who play as substitutes in groups that do not have 4 players have 0 added to their ranking (their ranking stays the same).

Other players may choose to join the ladder and their calculated rankings become the ranking assigned to them by the convener based on reported playing levels, subjective evaluations or just plain guesses. Their calculated ranking becomes this ranking +0.

The convener then looks at all the rankings and has a final say in the resultant “calculated” rankings. The convener then places the desired calculated rank in the override column and this override column becomes the final calculated rankings column.

All players are then placed in the order of their calculated rankings, ties resolved by their previous rankings. New rankings are then determined by player’s resultant positions.

Please note that this kind of ranking system may result in apparent anomalies. For instance, a better ranked player may not get as many points in his group as a lower ranked player but because of the difference in their beginning ranks the movement in the ladder may not be enough to move the player with more points in that group above the player that had fewer points. This prevents large movements that may just be accidental to one session.

The next playing session is setup with players who register for the session. They are then assigned to groups in the order of their rank. Thus, the first 4 players go in the first group based on their rank. Those may not be the top 4 players in the ladder, some of those top 4 may not have registered to play in that session.

The convener then assigns courts and times. Where possible the convener tries to accommodate times so that players travelling together get assigned to the same time slot. This is not always possible.

At the end of each playing session scores are entered into the computer and the whole process is repeated.

For the techies among you, this is all programmed in a single mysql query.