The Underlying Logic of Riichi and Chinese Official Mahjong, Part 2: Winning Requirements

Related article: The Underlying Logic of Riichi and Chinese Official Mahjong, Part 1: Payment Systems.

This installment continues the comparison through a central element of mahjong—winning requirements—to examine the two rulesets' design philosophies and the differences in national values behind them.

Japanese mahjong's emphasis on concealed hands

Concealment was not invented in Japan, but this scoring feature imported from China acquired a special place in Japanese mahjong. People often assume that since Japanese mahjong is Riichi Mahjong, and only concealed hands can declare riichi, concealment naturally has special value. In fact, the preference for concealed hands predates the spread of riichi. Rather than concealment becoming important because of riichi, riichi emerged because Japanese mahjong already valued concealment.

According to Ryō Asami and Makoto Fukuchi, this preference gradually developed after mahjong arrived in Japan. When the game first spread there in the 1910s, concealment initially earned only ten minipoints. Soon it became a central scoring feature and was promoted to one han. As scoring patterns became more widespread, pinfu—originally four chows and a pair with no minipoints—was also promoted to one han.

This created a conflict between pinfu and self-draw. Because pinfu meant having no minipoints, a discard win could score one han for it, but the two minipoints for self-draw prevented pinfu from applying. A self-drawn pinfu-shaped hand could therefore score less than a discard win, which seemed unreasonable. The initial Japanese solution was to award one han for a concealed discard win and two han for a concealed self-draw. This made the latter worth more. At that time, Japanese classical mahjong had not introduced the concept of concealed-only patterns; resolving the pinfu/self-draw conflict by making concealed self-draw worth one han more was an interesting approach. However, two han for concealed self-draw was plainly too much when patterns such as Half Flush and Mixed Outside Hand were worth only one han, upsetting the balance between concealment and other patterns.

The Japanese mahjong community therefore decided to hold a national meeting on the rules.

According to The Road to Modern Mahjong, representatives of 26 major Japanese mahjong organizations met on April 11, 1929, at what later became known as the Rainbow Conference. One of the most important issues in unifying the rules was how to treat concealment. The meeting established a basic principle: one han for concealed self-draw, and ten extra minipoints for a concealed discard win. This remained the mainstream scoring method for more than seventy years. Even so, concealed pinfu self-draw still scored less than concealed pinfu on a discard. The meeting therefore decided not to add self-draw minipoints when a concealed pinfu hand was self-drawn: it would count as 20 minipoints and two han. This is the rule commonly used in the Kantō region.

So does the one han for concealed self-draw reward concealment or self-draw? It rewards concealment, because a concealed discard win also earns extra minipoints, whereas an open self-draw earns no corresponding extra reward. More precisely, concealment is worth one han on self-draw and ten minipoints on a discard win.

The Japanese aesthetic preference behind concealment

The evolution of concealment's score shows that it has special meaning for Japanese players. This preference long predates riichi in 1953, and even full-discarder payment in 1931. Although both scholars describe the preference, neither deeply examines its underlying cause. It seems, once again, to have some connection with national character.

Here I offer a personal interpretation along the same lines as the discussion of full-discarder payment. I believe that Japanese mahjong's emphasis on concealment is closely connected to the value of not troubling others.

The payment-system article argued that this value is concentrated in the rule that the discarder pays alone. Full-discarder payment incorporates self-draw into the payment system and excludes an additional reward for it. This makes Japanese mahjong a game of heavy responsibility and limited reward, creating a restrained overall experience that seems consistent with Japanese society's reserve and self-control.

Yet the same value has another side. If not troubling others matters, behavior that avoids troubling others should also deserve praise. In mahjong, nothing is more self-contained than never calling a chow, pung, or other meld, assembling the entire hand through one's own draws, and winning by concealed self-draw. Since Japanese mahjong makes self-draw and discard wins equivalent in receipts, concealment itself acquires special value and deserves an additional score.

The term for concealment evokes a clean, undisturbed space in front of one's hand; in English it has been called a Fully private hand. Compared with a hand assembled through calls, a concealed hand looks tidier and more orderly, fitting Japanese aesthetic preferences.

Concealment first appeared in late Chinese classical mahjong. In Chinese mahjong, however, it is simply an ordinary scoring pattern. Chinese players see nothing wrong with calling other people's tiles. On the contrary, strategic calls are active ways of constructing a hand. Calling or not calling is merely a choice of strategy. Concealment means only that no exposed melds sit in front of the hand: it has no special value of not troubling others, no additional beauty, and no reward beyond its difficulty.

In Japanese classical mahjong, however, concealment earned either han or minipoints on both self-draw and discard wins, with a value even comparable to Half Flush and Mixed Outside Hand. Thus remaining concealed was a strategy with a substantial return. Combining concealment with the readily achievable pinfu and All Simples could easily reach 120 minipoints or more. Even before riichi, concealment, All Simples, and pinfu already formed the core Japanese route to a hand, and whether to remain concealed or call was already a classic strategic question.

Chinese mahjong's enthusiasm for new scoring patterns

Any discussion of Chinese mahjong must confront a question: with almost every province and city having its own regional rules, and dozens or hundreds of distinct systems nationwide, which one can truly be called “Chinese mahjong”?

Mahjong was banned on the Chinese mainland as a gambling instrument for decades. Only in the 1980s did regions begin reorganizing and restoring surviving rules. Although their patterns and details differed, many common features remained. In 1998, the national sports authorities organized experts to combine regional rules, with reference to Hong Kong, Taiwan, and Japan, into Chinese competitive mahjong rules, commonly called Chinese Official Mahjong. Although imperfect, it can be regarded as the most representative Chinese ruleset.

Its original purpose was to standardize domestic rules, make mahjong a healthy competitive activity, and move beyond its traditional association with gambling. However, its demanding character prevented widespread adoption. Meanwhile, regional rules generally simplified their scoring patterns and diversified into today's situation of a different ruleset in every locality.

Leaving the causes of regional diversity aside, I do not think these simplified rules represent Chinese mahjong. Its true evolutionary path runs from classical minipoint scoring and dealer-double payments, through Old Style fan scoring and discarder-double payments, to New Style's explosion of patterns, and finally Chinese Official Mahjong. The history of Chinese mahjong is fundamentally a process of increasing the number of scoring patterns and placing greater emphasis on hand-building.

The earliest classical mahjong centered on minipoints, with fan patterns playing a supporting role, but already included the classic aesthetic patterns based on uniform suits or structures: Full Flush, Half Flush, and All Pungs. Exceptionally rare and beautiful hands such as Big Three Dragons, Big Four Winds, Nine Gates, and Thirteen Orphans also existed. When Old Style shifted from minipoints to fan scoring, it added limit hands such as All Terminals and Honors, All Terminals, and Four Kongs. As a game, mahjong needed enough variety to satisfy the pleasure of building hands. From New Style onward, scoring patterns therefore multiplied rapidly, drawing on structural beauty, symbolism in tile designs, winning circumstances, and other ideas.

Mahjong books published in the 1980s recorded tournament rules with dozens or hundreds of patterns. The 1999 book Mahjong Studies included 391, while Encyclopedic Knowledge of Mahjong in 2004 listed more than 700 winning forms. Chinese Official Mahjong selected 81 from this accumulated popular tradition. Beyond that ruleset, the Hong Kong-style 16-tile Taiwanese mahjong popular in Hong Kong and Taiwan also has more than a hundred patterns, making it one of the richest currently popular regional systems.

The Chinese aesthetic preference behind pattern proliferation

Most Chinese mahjong players enjoy hand-building. They are not satisfied merely to complete a basic hand or win as quickly as possible; they prefer beautiful, difficult, high-value hands, which bring greater enjoyment and satisfaction. Big Four Winds, Nine Gates, and Quadruple Chow may be so difficult that a player never completes one in a lifetime, yet their very existence encourages continued challenges and the pursuit of an exceptional win. Providing different pattern series and adding high-value patterns is therefore a natural development that also deepens the game's entertainment and strategic possibilities.

Chows, pungs, and kongs are the natural means of actively reshaping a hand into a beautiful and difficult pattern. Hand-building necessarily relies on calls, while concealed draws depend entirely on luck and do not let players actively assemble those patterns. Thus concealment is fundamentally at odds with the philosophy of hand-building. From the Chinese perspective, concealment offers very little beauty compared with constructing a difficult large hand. It has consequently remained among the lowest-valued patterns in Chinese mahjong.

Japanese mahjong values concealment rather than hand-building, and its pattern system never experienced an explosion in numbers. Although it has added patterns over time, it has consistently been cautious about doing so, favoring a carefully selected repertoire. Numerous historical Japanese patterns are recorded, but there is no evidence that all were widely adopted nationally. Among the five main open-hand routes today, Half Flush and All Pungs already existed in Chinese classical mahjong; Pure Straight and the outside-hand series entered during the Japanese classical period; and Mixed Triple Chow was formally introduced only in modern Japanese rules. Since riichi spread in the 1950s, additions have mostly been unrelated to tile-pattern aesthetics, including ippatsu, ura-dora, and nagashi mangan. The preference for concealment makes many patterns difficult to complete without opening the hand. As discussed below, the basic Japanese choice is between concealed and open routes, so extra patterns have limited impact on that strategic framework.

Riichi: an enhanced form of concealment

As discussed above, the Japanese aesthetic preference strengthened the value of concealment, which could combine with pinfu and All Simples. These became the core strategy of Japanese classical mahjong. But this route was monotonous and did not satisfy the desire for large hands. Modern Japanese mahjong's most revolutionary element—riichi—emerged in response.

The biography A Lifetime of Riichi, about Taizō Amano, known as the father of riichi, describes its origin as follows:

In the autumn of Shōwa 24 (1951), Amano was supporting his family through work resembling black-market trading while also looking for opponents in newly opened mahjong clubs.

He regularly visited a parlor near Sugamo Station, not far from Takinogawa. One day, its owner asked him to devise a new scoring pattern.

“Could you come up with something that makes the game more exciting? The current league rules do not seem to bring in more customers.”

Amano folded his arms and thought. At a nearby table, one of four players suddenly shouted:

“I'm ready! Play anything strange and I'll win off it!”

He threw his tile into the discard area sideways, apparently without concern for etiquette. At that moment, Amano had an idea.

“That's it! When ready, declare ‘riichi,’ and from then on never change the hand. You can only win by self-draw or wait for someone to discard the tile you need. In return, the declaration earns one additional han. Turn the declaration discard sideways to make it clear. How does that sound?”

This history shows that riichi was fundamentally invented to make the game more exciting—more specifically, to make the concealed route more entertaining. Concealment works against hand-building; its easiest combinations are pinfu and All Simples, while large patterns such as All Pungs, Half Flush, and Full Flush are very unlikely in a concealed hand. Dora had not yet been introduced, so concealed play was both monotonous and unlikely to produce large hands.

Riichi gave concealed play a chance to double its score, strengthening that route, so it naturally found a warm reception in a community that valued concealment and quickly became widespread. Riichi reinforces concealment just as ippatsu and ura-dora later reinforced riichi: each recognizes and strengthens the preceding rule.

Meanwhile, main-route patterns expanded, including Mixed Triple Chow, and some values increased, such as Half Flush from one han to three. Riichi further balanced the relative importance of the concealed and open routes. It became the defining feature that gave the ruleset its name and ushered in the modern era of Japanese Riichi Mahjong.

Another Japanese tendency reflected in riichi

Riichi has both advantages and disadvantages from the perspectives of competition and skill, already discussed at length in A Historical Perspective on Zung Jung Mahjong. Even at the time of its introduction, there was opposition within Japanese mahjong:

In Shōwa 23, senior Japan Mahjong League figure Tokutarō Furuya published an article in Mahjong Times opposing riichi. He wrote that requiring players to discard whatever they drew after declaring riichi “greatly reduces the element of skill and degrades mahjong to the level of a simple card-flipping game.”

Amano was even summoned by the Metropolitan Police, who suspected that riichi would make mahjong more like gambling.

Some research traces riichi to Chinese ready-hand declarations. Yet in China these remained regional practices, while in Japan riichi quickly became a central rule. This suggests some compatibility with Japanese national character. What follows is my personal interpretation.

In my view, besides reinforcing concealment's aesthetic appeal, riichi reflects a Japanese appetite for going all in. As Furuya and Alan Kwan have argued, a riichi declaration is a wager: afterward, the player mechanically draws and discards, with no opportunity for skillful revision or a change of mind, accepting the outcome. It resembles going all in at the mahjong table. A concealed ready hand is followed by a ceremonial declaration discard, after which winning or dealing in is left to fate.

Among Japanese people in Manchuria, riichi was initially called “New Order” or “East Asia,” while double riichi was called “Greater East Asia”—all expressions current in militarist Japan. This brings to mind Japan's historical wagers on its national fortunes: several early successes followed by a catastrophic final loss. Might those national gambles also have stemmed from a preference for going all in, a mentality expressed in mahjong through riichi?

Chinese mahjong also has ready-hand announcements, but they are only one pattern among many, sometimes merely a local house rule, never the central mechanism they became in Japan. Chinese mahjong values flexible strategies for winning and building large hands. After becoming ready, a player may improve the hand's value, change waits for defense, or abandon the hand entirely. Riichi's prohibition on changing the hand plainly conflicts with this freedom of play.

Higher winning thresholds and hand-building

Chinese mahjong added numerous patterns to satisfy the desire to build hands. Large hands are beautiful but difficult, and mahjong is a race in which the first winner ends the hand. Numerous small, low-value hands therefore often interrupt large-hand attempts. Raising the minimum requirement for winning was a natural response.

The earliest minimum requirements appeared in Old Style mahjong, when pattern values were beginning to rise. All Pungs and Half Flush, for example, rose to three fan, forming the “three-three system.” Their increased value encouraged hand-building, but also increased the payoff from racing to win relatively small hands. Winning requirements consequently arose to restrain low-value quick wins and give larger hands a greater chance. The threshold gradually rose from merely forbidding Chicken Hand to a stable three-fan minimum.

As patterns expanded further, a winning threshold became essential to preserving hand-building and enjoyment. Whether the three-fan minimum in Old and New Style or the eight-point minimum in Chinese Official Mahjong, it became a basic feature of Chinese mahjong. Zung Jung, which has no minimum winning score, has demonstrated that however scientifically reasonable the pattern values may be, without a threshold the game falls into racing with small hands and cannot sustain a hand-building system.

Japanese mahjong, by contrast, values concealment rather than hand-building and has a much shorter pattern list. Classical Japanese mahjong had no minimum, while modern Riichi requires only one han—that is, a qualifying yaku. Fundamentally, Japanese mahjong has no need to raise this threshold and, in practice, cannot do so.

Winning requirements and hand-construction strategy

Because Japanese mahjong values concealment and includes riichi, its basic strategy is a choice between concealed riichi and an open hand. If the initial hand suggests an open route—small patterns such as value honors or All Simples, or the five main routes of flushes, All Pungs, outside hands, Pure Straight, and Mixed Triple Chow—the player can open the hand. Otherwise, remaining concealed, maximizing tile efficiency, and seeking riichi upon reaching readiness is optimal. Statistics suggest that these two routes account for roughly equal shares. This discussion has not yet incorporated later additions such as visible dora, red dora, ura-dora, and ippatsu, but they do not change the basic concealed-versus-open framework.

Chinese mahjong favors hand-building and larger hands, so it developed many buildable patterns and raised the winning threshold to increase their chances of completion. This creates a significant tension: more patterns and a higher threshold make a ruleset less accessible to beginners, a major criticism of Chinese Official Mahjong. Its 81 patterns, including more than thirty worth fewer than eight points, yield countless combinations for reaching the threshold and a steep learning curve. The precise threshold and pattern selection profoundly affect strategy. Changing the minimum to six or ten points, or removing All Chows or Mixed Shifted Chows, would transform play. Pattern selection and winning requirements are therefore the most central elements of hand-building mahjong.

A ruleset's hand-construction strategy is chiefly determined by its winning requirements, with the payment system playing a supporting role. The differences between Chinese and Japanese requirements and strategies reflect fundamental differences in aesthetic preference. As compensation for the principle of not troubling others, Japanese mahjong especially values concealment; riichi strengthens that route further. Choosing between concealment and opening forms its basic approach. Chinese mahjong promotes large hands, develops numerous aesthetic patterns, and raises the winning threshold to reduce interruption by small hands and increase large-hand completion.

As the payment-system discussion observed, values and aesthetic preferences are not inherently better or worse; the question is whether they suit the players. Chinese and Japanese mahjong each have their supporters and form their own systems.