The main event of WSoM 2018 continues to use the format which has been introduced in WSoM 2010 and continued in 2015. This format has the following aims:

  • The new format gives the players more playing time (guaranteed 16 cycles or 64 hands) before they are eliminated. In addition to providing more “value” for their entrance fee, this also mitigates the luck factor by giving the players more chances to exercise their skill.
  • The prize structure distributes the prize money according to one’s play score, thereby increasing the fun and excitement level throughout the tournament. It also spreads the prize money more evenly among a larger number of winners, so that there are more happy winners.

The organizer retains the right to modify these rules as needed. Though it is guaranteed that, the total prize pot as specified in “Prize Structure” item #1 will not be reduced.

Schedule Overview

  1. The World Series of Mahjong 2015 will be a 2-day event.
  2. Each day will be divided into 4 sessions of play, for a total of 8 sessions.
  3. The tournament consists of the preliminary round on the first day, and the final day rounds on the second day.
Day 1 Day 2
Preliminary round (4 sessions) Final day round 1 Final day round 2 Final day round 3 Grand final

The Preliminary Round

  1. The preliminary round consists of 4 sessions of play, on the first day of the event.
  2. All players play all 4 sessions. Each player’s match point score from all 4 sessions are totaled, and the top 32 players with the highest match point totals will receive prize money and advance into the final day rounds.
  3. In the unlikely event of a tie at the 32nd place, the tied players’ total raw score over the 4 sessions are compared to determine which player(s) advances into the final day rounds. If the raw scores are still tied, the advancing player will be picked randomly.

Match Point System

The match point (MP) system is adopted to encourage skillful, well-calculated play which steadily produces a positive score. Foolhardy play with an aim to win a high score when one gets lucky, but which tends to reap minus scores most of the time, is discouraged.

  1. In the preliminary round, a player’s score at the end of each session is first converted into match points before being totaled into his running score. (The match point system is not used during the final day rounds.)
  2. A player’s match point score for a session is simply the square root of his raw score. If a player has a negative score, the square root is applied to its magnitude.

A table is provided here with some sample values to help the player visualize the scores. The values are approximate.

session raw score +400 +300 +200 +100 +50  0 -50 -100 -200
match point +20 +17.3 +14.1 +10 +7.1 0 -7.1 -10 -14.1

Under this system, it is more important for a player to steadily earn a positive score every session, than to take reckless risks to attempt to get big scores. In particular, a player who succeeds in attaining a positive score (even some small ones) in each of the 4 sessions (on average attained by only 1/16 of the players) will most probably advance, and (assuming a total of 360 participants) about one out of every 9.5 players who attain a positive score in 3 sessions (on average attained by a quarter of the players) will advance.

The Final Day Rounds

  1. The final day rounds take place on the second day. Four rounds are played. Each round spans one session.
  2. The top 32 players from the preliminary round will enter the first final day round.
  3. At the end of each round (except the grand final), the players are ranked according to their scores for that round. The lower scoring half of the players will be eliminated, and the higher scoring half will advance to the next round. In addition, all players (including those being eliminated) receive prize money based on their scores for the round.
  4. In case of a tie in the session score at the cut-off rank, the player who has accumulated more prize money from previous rounds up to that point will advance. If this is also tied (a rare occurrence), the advancing player will be picked randomly.
f.d. round # 1 2 3 Final
# players 32 16  8 4
# advance 16 8 4

Players should note that, normally the total scores of all players in a session of mahjong should add up to zero (since the winner’s points are taken from his opponents). So it is expectable that about half of the players will get positive scores, while the other half will get negative scores. Thus, it is likely (although not guaranteed) that even a small positive score would suffice for advancement. Taking reckless risks to attempt to get big scores is more likely to eliminate the player than to help him advance (unless the player is already deep in the red and needs to catch up).

This tournament formats places an emphasis on getting positive scores (the “match point” system explained above also contributes to the same intent), instead of on one’s ranking within one’s table which is the focus of many other tournament formats. Players should take good note of this point.


  1. In each session, 4 cycles or 16 hands of mahjong will be played (unless truncated by the time limit). (Each cycle is 4 hands, and the deal always passes.)
  2. Each player starts each session with 0 points. The scores (plus or minus) from each hand alone constitute one’s result for the session; there are no additional bonus points for one’s rank at the table or such.
  3. For the preliminary round and the first two final day rounds, each session is divided into two halves, with 2 cycles (8 hands) in each half. Between the two halves, there is a break time, during which the players rotate tables (so that they will play against different opponents).
  4. At the beginning of each round, the organizer will randomly assign the players to the tables, and they will rotate tables according to a fixed pattern after each half. A “seating slip” will be issued to each player to direct him to the correct table.
  5. At the start of each half, the 4 players at a table will determine their seating order randomly. After one cycle of play, the starting East and North players will exchange their seats, and so will the starting South and West players (so that the upper and lower seat relations at the table will be reversed). After swapping seats, the player in the East seat (the starting North in the previous cycle, who has just been East in the previous hand) will become the starting East for the new cycle.

The 3rd Final Day Round

The 3rd final day round (the semi-final) follows a special schedule for table rotation, in order to provide better matchings when there are only 8 players in the round.

  1. The 3rd final day round consists of 4 quarters. In each quarter, one cycle (4 hands) will be played. Between quarters, the players rotate tables according to a special routine. There will be a break time after the second quarter.
  2. At the start of each quarter, the 4 players at a table will determine their seating order randomly.

The Grand Final

  1. The top 4 players will enter the grand final.
  2. At the beginning of the session, the 4 players will determine their seating order randomly.
  3. After each cycle of play, the original (first cycle) East and West players move (right) to the lower seat, and the original South and North players move (left) to the upper seat. After swapping seats, the player now sitting in the East seat will become the starting East for the new cycle. Thus, the original East starts the first cycle, the original South starts the second, the original West the third, and the original North the fourth.

Prize Structure

Instead of awarding fixed prize money according to rank, the players accumulate prize money from round to round. The prize money awarded depends on the player’s score for the round. As making the advancement cut-off is not the only goal, every point is valuable and every hand is important (even when the player is behind with slim hopes of making the cut).

  1. The total prize pot equals to 100% of the total entrance fees collected.
  2. The prize pot will be divided into five prize pools according to the ratios in the table below. Each prize pool corresponds to a round in the tournament.
    preliminary round pool 10%
    final day round 1 pool 15%
    final day round 2 pool 20%
    final day round 3 pool 25%
    grand final pool 30%
  3. The “preliminary round pool” will be distributed among the players whose preliminary round match point total scores are ranked within the top 32 players. Each winner receives prize money in direct proportion to his match point total. (In the extremely unlikely event that any of those players have a negative match point total, such players receive no prize money for the round.)
  4. In the unlikely event of a tie at rank 32 (the critical rank), the tie is not broken. Instead, the tied players split equally the amount due to the in-the-money rank(s). (Note that this rule applies to the distribution of the prize pool. A different rule applies concerning advancement.)
    Example: Three players are tied at 31st place with exactly 30 MP each. They share equally the prize money for the 31st and 32nd places; hence each of them receives 20 MP’s worth of prize money.
  5. Each of the final day round pools (including the “grand final pool”) will be distributed among all players in the corresponding round (including players who are being eliminated). At the end of each final day round, first 250 points are added to each player’s score in that round, then the players in the round divide the prize pool in direct proportion to their adjusted scores. If a player has lost over 250 points (and hence still has a negative score after adjustment), he receives no prize money for the round; in this case, the dollar value per point will be diluted accordingly (since the winners will have more points among them).
  6. A player must complete a round of play in order to be eligible for that round’s prize pool.
  7. Since the player accumulates prize money for his score, there is no longer any carry-over of scores from round to round.
  8. The prize money will be paid after the player has finished all his playing in the event. A player’s total prize money is rounded off to the nearest HK$.

Below is a table to help players visualize the prize structure. (The figures are based on the assumption that there are 360 players; actual figures may differ according to the number of players. The “$ value per point” is subject to dilution if some players score below -250 points. All monetary amounts are in HK$.)

Round Prize Pool # of Winners Average $ per Winner $ Value per Point
preliminary round 319,968 32 9,999 ?
final day round 1 479,952 14,999 60
final day round 2 639,936 16 39,996 160
final day round 3 799,920 8 99,990 400
grand final 959,904 4 239,976 960

Note that while the size of the prize pool is gradually increasing in later rounds, a much bigger factor is that there are fewer players sharing the prize pool in later rounds; hence the share received by each player in the round, and the money value of each point, will be skyrocketing. For example, a 40-point hand (such as Mixed One-Suit) in the grand final may be worth something like HK$ 115,188!

Session Time Limits

  1. For the preliminary round and final day rounds 1 and 2, the time limit for a “half” is 55 minutes, with a 10-minute break between the two halves. Total time will be 120 minutes per session.
  2. The time limit for a “quarter” (in final day round 3) is 27 minutes. There will be a 10-minute break after the 2nd quarter. For the 2nd and 4th quarters, both tables will start simultaneously. Total time for the round will be 118 minutes.
  3. If the time limit is up, the current hand should be finished as long as the tiles have been dealt completely. After finishing the current hand, the half or quarter is considered finished for the table, even if less than the specified number of hands have been played.
  4. At the TV table, special procedures which are required to facilitate filming the event may cause the play to be delayed. Hence, the organizer reserves the right to extend the session time limit at the TV table as appropriate.
  5. There is no session time limit in the grand final; the full 16 hands will always be played. (Note that per-hand “play time limits” still apply.) After 2 cycles, there will be a break time of 10 minutes.
  6. A player who does not show up when the break time is over will be considered late and penalized accordingly.
  7. If a table has not finished play at the commencement of the break time, it will continue playing into the break time to finish the current hand, which means that the players at the table will enjoy a shorter break accordingly.
  8. For the time limits for each player’s playing time in a hand, please see “Play Time Limits” in the “Mahjong Rules” chapter.
  9. A player who is leading in score may not deliberately take a time-out or exceed one’s play time limit with the purpose of reducing the number of hands to be played (so as to protect his lead). If the judges suspect a player of this violation, they have the right to require that the full number of hands be played regardless of the time limit, or impose an additional score penalty.

Player Teams

  1. Players who are family members or close friends etc. may elect to register as a team. Please refer to the registration instructions.
  2. During table assignment in final day rounds 1 to 3, the organizers will try to assign team members to different tables. Hence they can seize points from their opponents to their heart’s content without worrying about knocking their friends out of the competition. (Player teams are not considered during table assignment for the preliminary round.)
  3. Players may only be registered as a team with the consent of all players in the team.
  4. A team is limited to a maximum of 32 players.
  5. Team composition may be added or changed at any time, until the day before the first day of the event.
  6. The organizers will try to separate team members into different tables, but this is not guaranteed. Especially in the later rounds, it may become impossible to separate team members if many players from the same team succeed in advancing into the round. The organizers have full discretion as to which team members to separate and which to place together; the players have no right to alter team composition at that point to demand a desired split.

Announcement of Results

  1. After each round, the organizer will post the results after score calculation has been completed.
  2. Players should keep track of their own score record (please bring your own pen and paper). If one suspects an error, one may request a score checking. A handling fee of HK$50 will be charged for score checking (cash only); the money is refundable should a mistake on the part of the organizer is discovered.
  3. The posted results are subject to later correction. The final posted version is considered official.
  4. The organizer may also post or notify of the results after each session (in the preliminary round) or at any other time. A player may request score checking against these interim results in the same way (the handling fee is also required). Yet these are unofficial reports given for the purpose of entertaining the players and spectators; should there be any errors, the organizer’s responsibility goes no further than the correction itself of the errors. If a player adjusts his play strategy based on such reports, the organizer assumes no responsibility for any possible losses or disadvantage caused by any errors therein.
  5. After the conclusion of the event, the organizer will publish the final rankings. The final ranking is ordered based on the total accumulated prize money of each player, and may not necessarily correspond to the player’s play score ranking in his last played round.

Special Pardon for Late Arrival

To account for the possibility that a player’s travel to the venue might be delayed by external circumstances, such players are allowed to join the tournament in a later session. The rules in this section take precedence over other sections.

  1. A registered player who is absent during the first one or two session(s) of the preliminary round, but then checks in with the organizer before the start of the third session, will be allowed to play in the tournament thereafter.
  2. For each session the player is absent, a penalty of fifteen match points (15MP) is deducted from the player’s result.
  3. The organizer may refuse to allow a player to play in a session if he checks in later than 30 minutes before the start of the session.
  4. The above rules are only applicable to the first sessions of the preliminary round. A player who has played in one or more sessions but is then absent in a later session without an acceptable reason (the organizer has the final decision) will be eliminated for resignation; the player has no right to demand that the point penalty be applied instead.