LONGCATMIJ wins Mahjong Tournament in TCGA 2011 166
NEWS, INFORMATION, TOURNAMENTS, AND REPORTS
LONGCATMJ WINS MAHJONG TOURNAMENT IN TCGA 2011I-Chen Wu1, Yi-Chang Shan1, Cheng-Hung Lin1 and Shi-Jim Yen2
The first computer Mahjong tournament in the world was held as part of the TCGA 2011 computer game tournaments, which took place in Chang Jung Christian University, Tainan, Taiwan, from June 25th to 26th, 2011
(see Yen, Su, and Wu, 2011). Three teams participated in the Mahjong tournament. Table 1 lists the participants and the final standings. The three teams were LONGCATMJ, GRANDSLAM, and MAJO. They obtained 110,500;
59,000 and 11,500, respectively. Hence they won the gold, silver, and bronze medal in this order.
Ranking Program Author(s) Scores
1 LONGCATMJ Cheng-Hung Lin, and I-Chen Wu 110,500
2 GRANDSLAM Cheng-Wei Chou, and Shi-Jim Yen 59,000
3 MAJO Kai-Min Chuang, Yueh-Ju Chen, and Shun-Shii Lin 11,500 Table 1: The participants and final standings.
In general, the rules for Mahjong are quite complex. Besides, many different variations of Mahjong are using different rules in the world. This tournament used the version commonly played in Taiwan, which are described by Lin, Shan, and Wu (2011) in greater detail. The total tiles of Mahjong are 144 pieces, classified into six kinds of suits, which include Wan (ten thousand, or 萬 in Chinese), Tiao (rope, 條 or索), Tong (dot, or 筒), Wind (風), Dragon (箭) and Flower (花). Wan includes 1-Wan to 9-Wan; and Tiao and Tong are similar. Wind includes East, West, South, and North Winds; and Dragon has Red, Green and White Dragons. Each of them has four tiles. Flowers are related to extra bonus and have nothing to do with win-loss. Players initially obtain 16 tiles from a pool, and then take turns to bid a new tile (the 17th) and discard a tile to exchange tiles after bidding a tile.
In Mahjong, players win the game by making a winning pattern, including five sets of tiles and a pair of tiles (17 tiles in total). A set of tiles is either three identical tiles, say three Wans, or three consecutive tiles, say 2-Wan, 3-2-Wan, and 4-Wan. If a player A wins (or makes a winning pattern) by bidding a card discarded by another player B, it is said that A wins by Hu (胡) in Chinese. The player B is called Chucker. Only B loses
points SA(or scores) to A, where SA= VBase+ NT* VTai, where VBase and VTai are constants designated before
games, and NTis the number of Tais, calculated based on Mahjong rules (see Lin, Shan, and Wu, 2011). If the
player A wins by bidding one card from the pool, it is said that A wins by Self-Mo (自摸) in Chinese. All the other three players lose SA points to A. In Mahjong, the final winner is the one who obtains the highest number
of points (or scores). More rules and terminologies can be found in Lin, Shan, and Wu (2011).
Since the game is quite complex, this tournament leveraged the Mahjong network game system of a web game server, currently supported by ThinkNewIdea Ltd. The architecture of the tournament system is described in more detail in Lin, Shan, and Wu (2011). The following tournament rules are used (also for fairness without concerning uncertainty to a large extent).
1. The time limitation for each move of players is three seconds. 2. The values VBase and VTaiare 1000 and 500, respectively.
3. Since a Mahjong game needs four players, the tournament host used an additional program, named DUMMY. The DUMMY program never tried to win and always discarded the tile which it received.
4. 12 Jongs (將) are played. A Jong consists of four rounds. Each round has four games, in which each player serves as the dealer (or banker) once.
5. For each of the four games, the system uses the same random seed.
1 Dept. of Computer Science, National Chiao Tung University, Hsinchu, Taiwan, and Email:
{icwu,yschan,jhl}@java.csie.nctu.edu.tw.
2 Dept. of Computer Science and Information Engineering, National Dong Hwa University, Hualien, Taiwan, Email:
LONGCATMIJ wins Mahjong Tournament in TCGA 2011 167
Figure 1: The initial tiles of the game in the third round of the 11thJong.
The above rule 5 is important. For example, in the third round of 11th Jong, each dealer obtained the initial
cards, as those indicated with dotted line in Figure 1(a). Since the game favoured the dealer, each of the players (except DUMMY) won the game when serving as the dealer. Using the same random seed would make the
situation fairer.
Program Scores Numbers of winning games Number of Self-Mos
LONGCATMJ 110500 61 16
GRANDSLAM 59000 34 15
MAJO 11500 40 14
DUMMY -181000 0 0
Table 2: The statistics of Hus, Self-Mos, and Chuckers in tournament
According to the rules of Mahjong, the winner is the one who obtains the highest scores, instead of the one who obtains the highest number of winning games. From Table 2, we observe that LONGCATMJ won both, i.e., score and
number of winning games. However, GRANDSLAM won more scores than MAJO, while winning fewer games than MAJO. From our observation, GRANDSLAM won by Self-Mo with more Tais, implying more scores. This shows an
issue: should the tournament be ranked by scores or by the numbers of winning games? The three teams all agreed to use scores before tournament, since we wanted to make the tournaments as close to the original Mahjong as possible, though the three participants did not incorporate the issue into their programs. This is to be discussed in the next tournament.
F.l.t.r. Cheng-Hung Lin (Gold), Cheng-Wei Chou (Silver) and
Kai-Min Chuang (Bronze).
References
TCGA Computer Game Tournaments (2011). http://tcga.ndhu.edu.tw/tcga2011/.
The World Mahjong Organization. (2011). “Mahjoan Competition rules,” Chinese Publishing Company 2006. Retrieved from http://www.mindmahjong.com/info/eshowinfo.asp?id=447, 2006. Lin C.-H., Shan Y.-C. and Wu I-C. (2011). Tournament Framework for Computer Mahjong Competitions, International Conference on Technologies and Applications of Artificial Intelligence (TAAI, 2011).
ThinkNewIdea Limited. (2005). CYC Game (in Chinese). http://www.cycgame.com.
Shi-Jim Yen, Tsan-Cheng Su, and I-Chen Wu (2011). The TCGA 2011 Computer Games Tournament, ICGA Journal, Vol. 34, No. 2, pp. 108-110.
