Japanese mahjong scoring rules: Difference between revisions

[[Japanese mahjong]] features a very complex scoring system. Every mahjong hand has a value in terms of '''han''' and '''fu''' associated with them.  From a [[scoring table]], the combination of han and fu then corresponds to values indicated  These values are derived using han and fu into the [[#Calculating basic points|points equation]].

By default, most games start players at 25,000 points, with the goal of scoring at least 30,000 to declare victory for the points leader. Point settings may be flexible to vary both the starting score and the goal score.

'''Han''' {{kana|飜}} is the main portion of scoring, as each [[yaku]] is assigned a han number. Some may factor being open or closed; for others, this would not matter.  Any [[dora]] in the winning hand provides one extra han each. In general, an increase of value by one han roughly doubles the number of points, until the cap of [[#Scoring table|mangan]].

Yakuman do not have a han value. If a winning hand satisfies at least one yakuman, han and fu are not counted for the hand. Points are awarded based on the yakuman value; and if [[multiple yakuman]] are allowed, then the yakuman values are multipled by the number of yakuman patterns in the hand.  Finally, any hand that accumulates 13 or more han is counted for a [[kazoe yakuman]].

'''Fu''' {{kana|符}} (''pronounced as foo'') takes the hand composition into consideration in terms of [[mentsu|tile melds]], [[machi|wait patterns]] and/or win method. 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. Even a fu count of 32 gets rounded up to 40.  One exception falls on the [[chii toitsu]] yaku, which is fixed to 25 fu by default. While fu may be counted for hands worth 5 han or greater, it may no longer be necessary to count fu for [[Score table memorization|human memorization]]. Hands of this value become solely dependent on the han count, regardless of the fu count.  All-in-all, '''counting fu is most relevant for hands worth 4 han or less'''.

# If the hand is a [[List of yaku|yakuman]], then hand scores 8,000 basic points × number of yakuman.

# Otherwise, determine the hand's valid [[yaku]].

# Count the han based on the yaku.

# Count any number of dora to the han count.

# 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.

# After determining the number of han and/or fu, refer to the [[Scoring#Scoring table|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)}'''; limit of '''basic points = 2,000''', for [[mangan]] and beyond.

*When a non-dealer wins by tsumo, the player earns 1 × basic points from the other non-dealers.  The dealer in this case pays 2 × basic points.

*When the dealer goes out by tsumo, the dealer scores 2 × basic points from all players.

*When the dealer goes out by ron, the dealer earns 6 × basic points from the responsible non-dealer.

Finally with the multipliers applied, a hand's point value is finally expressed as:

'''Points = Basic points x Payment multiplier'''; points rounded up to the nearest 100.

 

The points derived from the equation and the payment multipliers are arranged in a scoring table. Players have the option of knowing the point scores by either deriving from the equation or [[Score table memorization|brute force memorization]].

'''Honba''' is an added counter to the number of consecutive hands, that did not produce a winning hand and/or the dealer position repeats.  For each honba count, every hand is worth a total of 300 extra points. Once a winning hand does occur, the honba count resets back down to zero.  The event of [[chombo]] may or may not produce a increase in the honba count; the common practice does not.

#Refer to the [[scoring table]], or [[Score table memorization|memorize the corresponding point values]]

At the end of the game, the raw points are used to calculate the end game score. These are the two or three digit +/- numbers used to reflect a player's score. Instead of 30,000 points, a player's score may actually be displayed as +40.0. <!-- To this day, I don't know why this system exists-->

'''Aotenjou''' {{kana|青天井}} is the practice of scoring hands without any limit imposed. This practice is rarely used, because without scoring limits, hands can produce ridiculously high point values. Naturally, that is induced by the exponential function of the basic points equation.

* [http://jbcs.info/Mahjong/hand/calculator.html Online hand scoring calculator]