Pinzu

Pinzu

Pinzu (筒子, ぴんず) is the circle suit in riichi mahjong, where each tile shows a number of circles equal to its value. A 1-pin tile shows one circle, a 5-pin shows five, a 9-pin shows nine in a 3-by-3 grid. Pinzu has 36 tiles in a standard riichi set (4 copies of each value 1-9). Most beginners find pinzu the easiest suit to read because counting circles is intuitive.

Pinzu in detail

Visual Identification

Each pinzu tile shows circles arranged in a consistent pattern across all manufacturers:

• 1-pin: single large circle in the center
• 2-pin: two circles diagonally
• 3-pin: three circles diagonally
• 4-pin: four circles in a 2-by-2 grid
• 5-pin: five circles in a quincunx pattern (4 corners + 1 center)
• 6-pin: six circles in two rows of three
• 7-pin: seven circles (3 + 1 + 3 arrangement is most common)
• 8-pin: eight circles in two rows of four
• 9-pin: nine circles in a 3-by-3 grid

The circles are usually drawn with concentric rings inside, mimicking the appearance of holed coins. Different manufacturers use different colors (red, blue, green, or mixed), but the count is what determines the value.

Origin of the Name

The name “pinzu” traces back to the Chinese tongzi (筒子, “tube” or “barrel”), referring to the rolls of strung coins that were the historical basis for the suit. In ancient Chinese currency, copper coins had square holes in the center for stringing onto bamboo rods, and a “tong” was a standard roll of 100 coins.

The visual pattern on each pinzu tile is a stylized depiction of those stacked coins viewed end-on. The 5-pin’s quincunx pattern is the same arrangement Chinese merchants used to count coins on a flat surface for thousands of years.

Pinzu in Riichi Strategy

Pinzu functions identically to manzu and souzu in riichi rules. The same yaku apply equally across all three suits, and there’s no scoring advantage to favoring one. What differs is reading speed, pinzu’s countable circles process faster visually than manzu’s Chinese numerals.

Many experienced players gravitate toward pinzu in flush-style hands (honitsu, chinitsu) because the rapid visual scan of circle counts speeds up their decision-making. This is a personal preference, not a strategic rule.

Pinzu’s 1 and 9 are terminal tiles, which matter for the same yaku as the other suits:

• Terminals 1-pin and 9-pin disqualify a tanyao hand
• They contribute to junchan and chanta (yaku requiring terminals in every set)
• They’re the only valid pinzu tiles in honroutou (terminals and honors only)

Pinzu Notation

Mahjong notation uses p for pinzu. So “1p” means 1 of pinzu, “5p” means 5 of pinzu, and “123p” means 1-2-3 sequence in pinzu. A standard sequence-style hand might be written 345m 678p 234s 99p 78s, meaning 3-4-5 manzu, 6-7-8 pinzu, 2-3-4 souzu, a pair of 9-pin, and 7-8 souzu waiting on 6 or 9 (13 tiles).

Walking through Pinzu

You’re dealt: 4p, 5p, 6p, 7p, 8p, 1s, 9s, 2m, 3m, 4m, west wind, white dragon, red dragon. You have a strong start in pinzu with five tiles already in sequence: 4-5-6-7-8. This positions you for either a 4-5-6 plus 7-8 (waiting on 6 or 9) or 6-7-8 plus 4-5 (waiting on 3 or 6). The terminal 1-souzu and 9-souzu hint at potential for a chanta hand if you can complete sets containing them, but you’d need to discard them and rebuild around manzu instead.