Scoring in Mahjong Competition Rules (Categorical)

For the sake of clarity, we will make a distinction here between yaku and points. Yaku are the types of ways your hand can score (In poker, Royal Flush or Two Pairs would both be examples of yaku). Points are how much each yaku adds to the value of your winning hand, which affects your overall score between hands.

A hand scores points equal to every yaku it scores, with one exception. If one single yaku cannot possibly be scored without another yaku (For example, a All Even Pungs hand by definition will always also be an All Pungs hand), only the most valuable of those yaku are scored; any yaku implied by the more valuable yaku are ignored.

Note that this only applies when one single yaku inevitably must include another yaku. For example, it's possible that a Little Four Winds hand will not have a pung of your seat wind, or a pung of the round wind (if your seat wind is the round wind, and that wind forms your pair). Therefore, no matter whether your seat wind is the round wind or not, you're permitted to score the yaku Pung of Seat Wind and the yaku Pung of Round Wind if either or both apply. As long as one possible counter example exists, you are free to score the yaku.

However, there are two notable exceptions to this rule though. There are only six different 'green' tiles, and six different terminal tiles. Therefore, in order to score either of these yaku along with a Seven Pairs, you must inevitably use all four copies of one tile to complete your hand. For whatever reason, the official rulebook notes that only in these circumstances, you are not allowed to also score 'Tile Hog' as well (These are the only cases in which a combination of two yaku together prevent you from scoring a third). In addition, because of this, you are forbidden from scoring both All Terminals and All Pungs (or Pung of Orphans) if you make it with four melds and a pair (Nor can All Honors or All Orphans, for whatever reason).

Please note that the exclusions listed for the yaku come from the official English translation of the China State Sports Commission's official rulebook. Therefore, though there may appear to be one or more exclusions not listed (such as a Four Gongs hand not having All Pungs or Three Gongs given as exclusions, despite being inherently a part of the hand), these are simply the official rules as they are given by the officials to be used. When applicable, I have added parenthetical remarks about exclusions listed in the original Chinese text of the official rulebook that are absent in the official English translation.

The following yaku are listed in order of the categories under which they are created and scored.

YAKU BASED ON HONOR TILES

Pung of Dragons (2 Points)
A triplet/quad of any of the three dragons.
Pung of Round Wind (2 Points)
A triplet/quad of the round wind.
Pung of Seat Wind (2 Points)
A triplet/quad of your own seat wind.
Double Dragons (6 Points)
A triplet/quad of any two of the three dragons. Though not even the original Chinese text of the official rulebook says as much, according to the Non-Repeat Principle, this yaku likely cannot stack with Pung of Dragons.
Big Three Winds (12 Points)
A hand including triplets/quads of three of the four winds.
Little Four Winds (64 Points)
A hand including triplets/quads of three of the four winds, and a pair of the fourth. Cannot stack with Big Three Winds or Pung of Orphans.
Little Three Dragons (64 Points)
Having a triplet of two of the dragons and a pair of the third. Cannot stack with Pung of Dragons or with Double Dragons.
All Honors (64 Points)
A hand made entirely of four triplets/quads and a pair of honor tiles, or of any seven pairs of honor tiles. Cannot stack with All Orphans. As a very odd exception to the rule, though an All Honors hand can be made with Seven Pairs, the official rulebook states that this hand cannot stack with All Pungs or Pung of Orphans.
Big Four Winds (88 Points)
A hand including triplets/quads of all four winds. Cannot stack with Big Three Winds, Pung of Seat Wind, Pung of Round Wind, All Pungs, or Pung of Orphans.
Big Three Dragons (88 Points)
A hand including triplets/quads of all three dragons. Cannot stack with Pung of Dragons or with Double Dragons.

YAKU BASED ON TERMINAL TILES

All Simples (2 Points)
A hand that contains only simple tiles. That is, no 1's, 9's, or honor tiles.
All With Orphans (4 Points)
A hand in which every meld contains an orphan tile, and the pair is of orphan tiles. That is, every run is 1-2-3 or 7-8-9, and all triplets/quads are 1's, 9's, or honor tiles.
Upper Four (12 Points)
A hand composed entirely of tiles with the numbers 6, 7, 8, or 9. Cannot stack with No Honors.
Lower Four (12 Points)
A hand composed entirely of tiles with the numbers 1, 2, 3, or 4. Cannot stack with No Honors.
All Fives (16 Points)
A hand in which every meld contains a tile with the number 5, and the pair is of 5's. That is, every run is 3-4-5, or 4-5-6, or 5-6-7, and all triplets/quads are 5's. Cannot stack with All Simples.
Upper Tiles (24 Points)
A hand composed entirely of tiles with the numbers 7, 8, or 9. Cannot stack with No Honors or Upper Four.
Middle Tiles (24 Points)
A hand composed entirely of tiles with the numbers 4, 5, or 6. Cannot stack with No Honors or All Simples.
Lower Tiles (24 Points)
A hand composed entirely of tiles with the numbers 1, 2, or 3. Cannot stack with No Honors or Lower Four.

YAKU BASED ON CHOWS

Pure Double Chow (1 Point)
A hand with two identical runs in the same suit.
Two Colors, One Chow (1 Point)
A hand with an identical run in two of the suits. For example, a 4-5-6 in bamboo and a 4-5-6 in characters.
Short Straight (1 Point)
A hand containing two consecutive runs. For example, a 3-4-5 dots and a 6-7-8 dots.
Two Terminal Chows (1 Point)
A hand containing two runs of 1-2-3 and 7-8-9 in the same suit.
All Chows (2 Points)
A hand composed entirely of four runs and a pair, where the pair is not made of honor tiles. Cannot stack with No Honors.
Mixed Chained Chows (6 Points)
A hand with three runs in all three suits, where the lowest-numbered tile of every run is one number greater than the last. For example, a 3-4-5 in dots, a 4-5-6 in bamboo, and a 5-6-7 in characters.
Mixed Straight (8 Points)
A hand which contains a run of 1-2-3 in one suit, a run of 4-5-6 in a second suit, and a run of 7-8-9 in the third suit.
Three Colors, One Chow (8 Points)
A hand with an identical run in all three suits. For example, a 3-4-5 in dots, a 3-4-5 in bamboo, and a 3-4-5 in characters.
Large Straight (16 Points)
A hand which contains a run of 1-2-3, a run of 4-5-6, and a run of 7-8-9 all in the same suit.
Mixed Terminal Chows (16 Points)
A hand containing two runs of 1-2-3 in two suits, two runs of 7-8-9 in the same two suits, and a pair of 5's in the third suit. For example, 1-2-3 dots, 1-2-3 bamboo, 7-8-9 dots, 7-8-9 bamboo, 5-5 characters. Cannot stack with No Honors; All Chows; Two Colors, One Chow; or Two Terminal Chows.
Three Chained Chows (16 Points)
A hand with three runs in the same suit, where the lowest-numbered tile of every run is either one number greater than the last, or the lowest-numbered tile of every run is two numbers greater than the last. For example, a 1-2-3 in bamboo, a 3-4-5 in bamboo, and a 5-6-7 in bamboo. Alternatively, a 3-4-5 in dots, a 4-5-6 in dots, and a 5-6-7 in dots.
Pure Triple Chow (24 Points)
A hand with three identical runs in the same suit. Cannot stack with Pure Double Chow.
Four Chained Chows (32 Points)
A hand with four runs in the same suit, where the lowest-numbered tile of every run is either one number greater than the last, or the lowest-numbered tile of every run is two numbers greater than the last. For example, a 1-2-3 in bamboo, a 3-4-5 in bamboo, a 5-6-7 in bamboo, and a 7-8-9 in bamboo. Alternatively, a 3-4-5 in dots, a 4-5-6 in dots, a 5-6-7 in dots, and a 6-7-8 in dots. Oddly enough, even though a Four Chained Chows hand will always include either a Short Straight or a Two Terminal Chows (but never both), the official rulebook claims that this yaku is not allowed to stack with either of those yaku. This is a rare exception to the Non-Repeat Principle's methods.
Pure Quadruple Chow (48 Points)
A hand with four identical runs in the same suit. Cannot stack with Tile Hog or Pure Triple Chow.
All Terminals (64 Points)
A hand made entirely of four triplets/quads and a pair of terminal tiles (1's or 9's). Alternatively, the hand can be made of any seven pairs of terminal tiles. Cannot stack with All Orphans or No Honors. Alternatively, the hand can be made of any seven pairs of terminal tiles. Cannot stack with All With Orphans or No Honors. As a very odd exception to the rule, though an All Terminals hand can be made with Seven Pairs, the official rulebook states that this hand cannot stack with All Pungs or Pung of Orphans. Additionally, a hand that scores both All Terminals and Seven Pairs is arbitrarily not allowed to score Tile Hog as well.
Pure Terminal Chows (64 Points)
A hand containing two runs of 1-2-3 in one suit, two runs of 7-8-9 in the same suit, and a pair of 5's in the same suit. That is, the final hand is 1-1-2-2-3-3-5-5-7-7-8-8-9-9 in the same suit. Cannot stack with Full Flush, All Chows, Pure Double Chow, or Two Terminal Chows.

YAKU BASED ON PUNGS AND GONGS

Pung of Orphans (1 Point)
A hand containing a triplet/quad of 1's, 9's, or any of the wind tiles other than your seat wind or the round wind. Since a triplet/quad of dragon tiles, of the seat wind, or of the round wind already scores points, they do not count as a Pung of Orphans for scoring.
Open Gong (1 Point)
A hand containing one open/promoted quad.
Two Colors, One Pung (2 Points)
A hand with an identical triplet in two of the suits. For example, a 4-4-4 in dots and a 4-4-4 in characters. One or both of these triplets may be quads instead.
Two Concealed Pungs (2 Points)
A hand in which two of its triplets/quads are concealed melds. If you declare a win off of another player's discard, and that discard completes the third triplet, your hand cannot score this yaku: You must draw all of the tiles for the three triplets/quads from the wall.
Concealed Gong (2 Points)
A hand containing one concealed quad.
Two Open Gongs (4 Points)
A hand containing two open/promoted quads. If your hand contains one open/promoted quad and one concealed quad, it scores this yaku as well as the yaku for Concealed Gong.
All Pungs (6 Points)
A hand composed entirely of four triplets/quads and a pair.
Mixed Chained Pungs (8 Points)
A hand with triplets/quads of three consecutive numbers in all three suits. For example, a 3-3-3 in dots, an 4-4-4 in bamboo, and a 5-5-5 in characters.
Two Concealed Gongs (8 Points)
A hand containing two concealed quads.
Three Colors, One Pung (16 Points)
A hand with an identical triplet in all three suits. For example, a 2-2-2 in dots, a 2-2-2 in bamboo, and a 2-2-2 in characters. One or more of these triplets may be quads instead.
Three Concealed Pungs (16 Points)
A hand in which three of its triplets/quads are concealed melds. If you declare a win off of another player's discard, and that discard completes the third triplet, your hand cannot score this yaku: You must draw all of the tiles for the three triplets/quads from the wall. Instead, it would score Two Concealed Pungs.
All Even Pungs (24 Points)
A hand composed entirely of four triplets/quads and a pair, where every tile in your hand is a 2, 4, 6, or 8. Cannot stack with All Pungs or with All Simples.
Three Chained Pungs (24 Points)
A hand with triplets/quads of three consecutive numbers in the same suit. For example, a 7-7-7 in dots, an 8-8-8 in dots, and a 9-9-9 in dots.
Three Gongs (32 Points)
A hand with three quads, whether they're promoted, open, concealed, or a mix of the three. There is an ongoing controversy between officials over whether or not you may also score yaku for any combinations of Two Concealed Gongs, Two Open Gongs, Concealed Gong, or Open Gong that apply to your hand.
All Orphans (32 Points)
A hand in which every tile is an orphan tile. That is, a hand where all four triplets/quads and the pair are 1's, 9's, or honor tiles. Alternatively, the hand can be made of any seven pairs of orphan tiles. Cannot stack with All With Orphans. As a very odd exception to the rule, though an All Terminals hand can be made with Seven Pairs, the official rulebook states that this hand cannot stack with All Pungs or Pung of Orphans.
Four Chained Pungs (48 Points)
A hand with triplets/quads of four consecutive numbers in the same suit. For example, a 2-2-2 in bamboo, a 3-3-3 in bamboo, a 4-4-4 in bamboo, and a 5-5-5 in bamboo. Cannot stack with Three Chained Pungs or All Pungs.
Four Concealed Pungs (64 Points)
A concealed hand of four triplets/quads and a pair. You may only win by discard to complete the pair: All four triplets must be entirely self drawn. Cannot stack with All Pungs or Concealed Hand.
Four Gongs (88 Points)
A hand made of four quads and a pair. Cannot stack with Single Wait (And though it's not mentioned in the official translation of the rulebook, the original Chinese says that this yaku cannot stack with All Pungs. There is no definitive restriction on whether or not it can stack with Three Gongs, but it presumably cannot, based on the Non-Repeat Principle of scoring). There is an ongoing controversy between officials over whether or not you may also score yaku for any combinations of Two Concealed Gongs, Two Open Gongs, Concealed Gong, or Open Gong that apply to your hand.

YAKU BASED ON PAIRS

Seven Pairs (24 Points)
A hand composed entirely of any seven pairs. A Seven Pairs hand cannot count any yaku that specifically require runs, triplets, or quads. Cannot stack with Concealed Hand or Single Wait.
The Chariot (88 Points)
A concealed hand that contains seven distinct pairs of tiles in one suit, each tile one number greater than the last. That means the final pattern must always be 1-1-2-2-3-3-4-4-5-5-6-6-7-7, or 2-2-3-3-4-4-5-5-6-6-7-7-8-8, or 3-3-4-4-5-5-6-6-7-7-8-8-9-9, all in the same suit. Cannot stack with Full Flush, Concealed Hand, or Single Wait (And though it's not mentioned in the official translation of the rulebook, the original Chinese says that this yaku cannot stack with Seven Pairs).

YAKU BASED ON SUITS

One Voided Suit (1 Point)
A hand that only uses two of the three suits. The hand may or may not use honor tiles.
No Honors (1 Point)
A hand that does not use any honor tiles.
Half Flush (6 Points)
A hand composed of only one suit and honor tiles.
Five Types (6 Points)
A hand made of four melds and a pair, where between the four melds and the pair, there are dot tiles, bamboo tiles, character tiles, dragon tiles, and wind tiles.
Full Flush (24 Points)
A hand composed entirely of one suit. Cannot stack with Half Flush or No Honors.
Perfect Green (88 Points)
A hand made entirely of tiles printed exclusively in green ink. These tiles included the Green Dragon, 2-bamboo, 3-bamboo, 4-bamboo, 6-bamboo, and 8-bamboo. A hand that scores both Perfect Green and Seven Pairs is arbitrarily not allowed to score Tile Hog as well.
Nine Gates (88 Points)
A concealed hand that contains specifically 1-1-1-2-3-4-5-6-7-8-9-9-9 in the same suit, followed by winning with any other tile in that same suit. Cannot stack with Full Flush, Concealed Hand, or Pung of Orphans.

YAKU BASED ON KNITTED TILES

Knitted Straight (12 Points)
A hand containing three knitted melds. That is, 1-4-7 in one suit, 2-5-8 in a second suit, and 3-6-9 in a third suit. The completion of a knitted meld can never be considered an Edge Wait or Closed Wait, but these yaku can still be scored if your fourth meld uses one of these waits. Since knitted melds are scored as chows, this hand can be combined with All Chows if the fourth meld and pair fit the criteria for that.
Lesser Knitted Honors (12 Points)
A hand made up of fewer than seven unique honor tile and any other unique tiles that can form knitted melds (that is, any of 1-4-7 in one suit, any of 2-5-8 in a second suit, and any of 3-6-9 in the third suit). Your hand must not contain any pairs. Despite the fact that the tiles in this hand are not considered to be in any melds, this yaku can stack with Knitted Straight if it uses only five unique honor tiles. The completion of a knitted meld can never be considered an Edge Wait or Closed Wait. Cannot stack with All Types or Concealed Hand (This yaku cannot qualify for Single Wait since it contains no pairs).
Greater Knitted Honors (24 Points)
A hand made up of one of every honor tile and any other seven unique tiles that can form knitted melds (that is, any of 1-4-7 in one suit, any of 2-5-8 in a second suit, and any of 3-6-9 in the third suit). Your hand must not contain any pairs. The completion of a knitted meld can never be considered an Edge Wait or Closed Wait. Cannot stack with All Types or Concealed Hand (This yaku cannot qualify for Single Wait since it contains no pairs).

YAKU BASED ON WINNING

Edge Wait (1 Point)
Your waiting pattern for your hand is either 1-2 waiting for a 3, or 8-9 waiting for a 7. There must be no tile other than that one that you may use to win.
Closed Wait (1 Point)
The waiting pattern for your hand has a closed wait. For example, a 3-5 dots waiting on the 4-dots. There must be no tile other than that one that you may use to win.
Single Wait (1 Point)
The waiting pattern for your hand is to complete the pair. There must be no tile other than that one that you may use to win.
Self-Pick (1 Point)
Drawing the winning tile yourself.
Concealed Hand (2 Points)
A hand made without any open melds, in which you win off of another player's discarded tile.
Fully Concealed (4 Points)
A hand made without any open melds, and in which you draw the winning tile yourself. Certain yaku cannot stack with Concealed Hand, but all yaku can stack with Fully Concealed. Though not even the original Chinese text of the official rulebook says as much, according to the Non-Repeat Principle, this yaku likely cannot stack with Self-Pick.
Dead Tile (4 Points)
The tile you win with (either by self-pick or off of another player's discard) must be the last copy of that tile available: The three other copies must be in open melds or discarded.
Melded Hand (6 Points)
A hand with four open melds, won off of a discarded tile. Cannot stack with Single Wait.
Last Tile Draw (8 Points)
Drawing the very last tile in the wall and using it to win. In this mahjong style, the Chinese name for this yaku translates to "miracle cure" or "hands which bring the dead back to life". Cannot stack with Self-Pick.
Last Tile Discard (8 Points)
Winning with the last discard in the game, made immediately after the live wall runs out of tiles.
Win Off a Gong Replacement (8 Points)
Winning with the replacement tile drawn from a quad. Unlike most styles of mahjong, if the replacement tile is the last tile of the live wall, you also score 8 Points for Last Tile Draw. Cannot stack with Self-Pick.
Robbing a Gong (8 Points)
Winning off of a tile used to made a promoted quad. Scored as a win by discard against the player making the promoted quad. Cannot stack with Dead Tile.

YAKU BASED ON SPECIAL QUALITIES

Bonus Tiles (1 Point)
Drawing any of the bonus tiles. You score one point for every bonus tile you draw. Points from this yaku cannot contribute to the 8 point minimum your hand must score in order to declare a win.
Tile Hog (2 Points)
Using all four copies of a tile in two or more melds, or in one or more meld with the pair. That is, using all four copies of a tile without using them in a quad.
Symmetrical Tiles (8 Points)
A hand made up exclusively of tiles with vertical reflectional symmetry. That is, 1-2-3-4-5-8-9 dots, 2-4-5-6-8-9 bamboo, and white dragon. As a very odd exception to the rule, though a Symmetrical Tiles hand can be made as a Half Flush or Full Flush, the official rulebook states that this hand cannot stack with One Voided Suit.
Chicken Hand (8 Points)
A hand that would otherwise receive 0 points (with the exception of Bonus Tiles). That is, the hand must meet all of the following requirements:
  • The hand must be made of four melds and a pair. Your melds cannot involve knitted runs.
  • Your pair must be made of honor tiles, but none of your melds can be made of honor tiles. Your melds must not include any quads, must have at least one run, and at most one concealed triplet.
  • Your melds must involve all three suits: Dots, bamboo, and characters.
  • You must have at least one open meld, but fewer than four open melds.
  • You must win off of a discarded tile which is not the last copy of that tile available, which is not used to create a promoted quad, which is not the last discard of the game, and from a waiting pattern in which two or more tiles could complete your hand.
  • At least one of your melds must be made exclusively with simple tiles (That is, without any 1's or 9's).
  • You may not use all four copies of any tile in your hand.
  • You must not have any identical triplets in two suits, or three consecutive triplets in all three suits. None of your triplets can be 1's or 9's.
  • You must not have any identical runs (either in the same suit or in separate suits). You must not have two consecutive runs in the same suit, or both a run of 1-2-3 and a run of 7-8-9 in the same suit.
  • You must not have three consecutive runs, or three runs where the lowest-numbered tile of every run is one number greater than the last.
Thirteen Orphans (88 Points)
A hand made up of one of every honor tile, one of every terminal tile, and any other copy of any other these tiles. Cannot stack with All Types, Concealed Hand, or Single Wait (And though it's not mentioned in the official translation of the rulebook, the original Chinese says that this yaku cannot stack with All Orphans).

SCORING

Your hand must score at least 8 points in order for you to declare a win, regardless of any points earned from Bonus Tiles. Add together all of the points of your hand, following the MCR five principles for scoring:
  • The Non-Repeat Principle: If a single yaku inevitably implies a less valuable yaku, only the more valuable yaku is scored: The implicit ones are ignored.
    • If two yaku together imply a third yaku (e.g., a hand that scores Perfect Green and Full Flush mush always score All Simples, but neither Perfect Green nor Full Flush inherently imply All Simples), the implied yaku is still scored. A yaku is ignored only if it is implicit in one single yaku scored in your hand.
    • If yaku A is implicit in yaku B, and yaku B is implicit in yaku C, then yaku A is implicit in yaku C. For example, The Chariot's description states that it cannot stack with Full Flush. Full Flush's description states that it cannot stack with No Honors. Therefore, The Chariot also cannot stack with No Honors, even though it's not explicitly stated in its description.
  • The Non-Separation Principle: You must decide on one particular layout for your hand. You could not treat a 1-1-1-2-2-2-3-3-3 dots as both three pungs and three chows for the purposes of scoring: You must choose one or the other.
  • The Non-Identical Principle: Once a meld has been used with one other meld to create a yaku, it cannot be used with a second different meld to score the same yaku again (For example, if you have 1-2-3 dots, 1-2-3 dots, 4-5-6 dots, and 7-8-9 dots, you can only score Large Straight once. You cannot use both of your 1-2-3 dots to score two separate Large Straights).
  • The Freedom of Choice Principle: If you can use a meld to score one of two (or more) separate yaku, you're free to choose to score the more valuable yaku.
  • The Account-Once Principle: Once you have chosen the first yaku you wish to score, any melds not used to score that yaku can only be used once for scoring other yaku (For example, if you have 1-2-3 dots, 1-2-3 dots, 4-5-6 dots, and 7-8-9 dots, in addition to scoring Large Straight, you can use the remaining meld of 1-2-3 dots to score only one of Short Straight, Pure Double Chow, or Two Terminal Chows. You cannot score more than one of those yaku, since you'd be adding your remaining meld with multiple different melds).
Once you have the final value of your hand after following these five principles, points are to be transferred. If you self-pick your win, all other players pay you the value of your hand, plus 8 additional points as a bonus for winning. If you win off of a discarded tile, the player who discarded it pays you the value of your hand, plus 8 additional points as a bonus for winning. The other two players pay you simply 8 points.

1 comment:

  1. Hi! Thanks for this blog post. I'm learning this version after playing Mahjong Riichi for a while so the scoring is taking a while to get a hang of.

    I'm wondering why you place All Terminals in the Yaku based on Chows instead of Yaku based on Pungs? Is that a mistake?

    All the best,
    Sig

    ReplyDelete