Pinfu

What is Pinfu in Japanese Mahjong?

Pinfu is a one-han yaku in Japanese Riichi Mahjong that emphasizes a purely sequence-based hand structure with no additional fu (minipoints) coming from the waits or the pair. Pinfu is a cornerstone yaku of Japanese Riichi Mahjong. It requires four runs, a non-scoring pair, a two-sided wait, and a fully concealed hand that generates no additional fu. While it only awards one han on its own, Pinfu often stacks seamlessly with other yaku like Riichi, All Simples, and Fully Concealed Hands, making it a versatile and commonly pursued strategy for both novice and experienced players alike.

How to Achieve Pinfu？

Four Runs (Chows):Your hand must consist of four sequences (e.g., 1-2-3 dots, 4-5-6 characters, etc.).No pung (three-of-a-kind) or exposed sets are allowed if you want to qualify for Pinfu.

Valueless Pair:The pair in your hand cannot be any honor tile that awards fu on its own (seat wind, round wind, or any dragon). If your pair is a special wind or dragon, you gain extra fu, disqualifying you from Pinfu.

Two-Sided Wait: You must be waiting on a two-sided run. For instance, in a 4-5 sequence, waiting on 3 or 6. Single-tile waits, edge waits (e.g., waiting on 1 in a 1-2 sequence), or inside waits (e.g., waiting on 5 in 4-6) all yield additional fu and thus invalidate Pinfu.

Fully Concealed: Pinfu requires a concealed hand (no chow/pung/open kong). Concealed kong are still considered “closed” for yaku purposes, but note that forming a kan might alter your hand structure and waiting shape, so it’s situational.

No Additional Fu: The essence of Pinfu is that the hand generates no extra fu beyond the base 20 fu for a concealed hand.

Pinfu Score Calculation

One Han: Pinfu is worth one han.

Often combined with other yaku to boost overall score, such as:

• Riichi : Another one-han yaku for a concealed, ready hand.
• Fully Concealed Hands: Self-drawing a fully concealed hand gives an additional one han.
• All Simples: If all tiles are simples (2–8), Pinfu can stack with All Simples for more points.

What is the Strategy and Risk of Pinfu?

Efficient Hand Shapes: A hand designed for Pinfu typically uses many sequences, which often leads to more flexible waits (e.g., two-sided waits). This can improve your chances of completing the hand quickly.

Reduced Fu, Possibly Higher Han: Even though Pinfu yields no extra fu, combining it with Riichi, All Simples, or Fully Concealed Hands can significantly increase the final score thanks to added han and potential dora.

Avoiding Honor Pairs: Because using an honor tile as a pair usually negates Pinfu, players might avoid pairing up winds or dragons (unless specifically targeting a yakuhai hand).

Concealed-Only Strategy: Pinfu demands that the hand remain concealed, which can slow down progress if a potential meld would speed up your wait. However, the payoff can be higher with additional yaku and dora bonuses.

Core Building Block: Pinfu is considered a foundational concept. Understanding how to create and maintain a Pinfu structure is vital for balanced and efficient Riichi Mahjong play.