Japanese mahjong scoring rules

Japanese mahjong features a very complex scoring system. Every mahjong hand has a value in terms of han and fu associated with them. The combination of han and fu then corresponds to values indicated from the scoring table, and/or the two numbers of han and fu factor into an equation, by which the scoring table is derived.

Scoring factors

Han

Main article: List of yaku

Each yaku is assigned a han number. Some may factor being open or closed; for others, this would not matter.

Yakuman are set to a base han of 13.

Fu

Fu (符) takes the hand composition into consideration in terms of tile melds, wait patterns and/or win method. In addition, every hand begins with a default start value of 20 fu. To determine the final number of fu, the sources of fu are added up along with the base number and then rounded up to the nearest 10. One exception falls on the chii toitsu yaku, which is set to 25 fu by default.

Fu factors into the following elements:

Melds

English	Romaji	Fu value
Open wait	Ryanmen	0
Closed wait	Kanchan	2
Edge wait	Penchan	2
Pair wait	Tanki	2

Scoring procedure

Calculating basic points

To determine the point value of a hand, the following procedure is used:

1. If the hand is a yakuman, then hand scores 8,000 basic points × number of yakuman.
2. Otherwise, determine the hand's valid yaku.
3. Count the han based on the yaku.
4. Count any number of dora to the han count.
5. If the han count is 5 or more, then counting fu is no longer necessary. Score the hand according to its han value on the scoring table.
6. If the han count is 4 or less, then count fu.
7. After determining the number of han and/or fu, refer to the scoring table.

For any who prefer to use the equation, basic points for 5 han or less are computed as

Basic points = fu × 2^{(2 + han)}, using basic points = 2,000 if the former exceeds 2,000

Payments

After determining the basic points, multiply based on the status as dealer and no-dealer as well as the win by ron or tsumo.

• When a non-dealer wins by tsumo, the player earns 1 × basic points from the other non-dealers, rounded up to a full 100. The dealer in this case pays 2 × basic points, rounded up to a full 100.
• When a non-dealer wins by ron, the discarding player pays the winner 4 × basic points, rounded up.
• When the dealer goes out by tsumo, the dealer scores 2 × basic points from all players, rounded up.
• When the dealer goes out by ron, the dealer earns 6 × basic points from the responsible non-dealer, rounded up.

Honba

In the event of ryuukyoku or a dealer win, the honba or tsumibou count increases by 1 for the next hand. If someone wins a hand and East does not, the honba count resets back to zero.

This count increases hand values increases by a total of 300 per honba. For ron, the discarder pays the additional 300 points. For tsumo, everyone pays an additional 100 each. These extra points are added to the hand value after the capping as mangan, haneman, etc., so a non-dealer mangan tsumo with 2 honba costs 2,200 for a non-dealer and 4,200 for the dealer.

In the case of sekinin barai, the yakuman tsumo payment is borne entirely by the discarder of the ponned tile, who also has to pay 300 per honba. On a ron, the yakuman value is split between the discarder of the winning tile and the discarder of the earlier ponned tile. Most rules have the winning tile discarder pay for all honba.

Scoring table

Dealer

Han/Fu	20	25	30	40	50	60	70	80	90	100	110
1 han	-- --	-- --	500 1500	700 2000	800 2400	1000 2900	1200 3400	1300 3900	1500 4400	1600 4800	1800 5300
2 han	700 2000	-- 2400	1000 2900	1300 3900	1600 4800	2000 5800	2300 6800	2600 7700	2900 8700	3200 9600	3600 10600
3 han	1300 3900	1600 4800	2000 5800	2600 7700	3200 9600	3900 11600	4000 12000
4 han	2600 7700	3200 9600	3900 11600	4000 12000
Mangan (5 han)	4000 12000
Haneman (6,7 han)	6000 18000
Baiman (8,9,10 han)	8000 24000
Sanbaiman (11,12 han)	12000 36000
Yakuman (13+ han)	16000 48000

Nondealer

Han/Fu	20	25	30	40	50	60	70	80	90	100	110
1 han	-- --	-- --	300/500 1000	400/700 1300	400/800 1600	500/1000 2000	600/1200 2300	700/1300 2300	800/1500 2900	800/1600 3200	900/1800 3600
2 han	400/700 1300	-- 1600	500/1000 2000	700/1300 2600	800/1600 3200	1000/2000 3900	1200/2300 4500	1300/2600 5200	1500/2900 5800	1600/3200 6400	1800/3600 7100
3 han	700/1300 2600	800/1600 3200	1000/2000 3900	1300/2600 5200	1600/3200 6400	2000/3900 7700	2000/4000 8000
4 han	1300/2600 5200	1600/3200 6400	2000/3900 7700	2000/4000 8000
Mangan (5 han)	2000/4000 8000
Haneman (6,7 han)	3000/6000 12000
Baiman (8,9,10 han)	4000/8000 16000
Sanbaiman (11,12 han)	6000/12000 24000
Yakuman (13+ han)	8000/16000 32000

External links

Online hand scoring calculator