What is Penchan Machi? Edge Wait Pattern and Tactics Explained for Beginners

What is Penchan Machi (Edge Wait)?

Penchan machi (辺張待ち) is a tenpai pattern waiting for with , or waiting for with . It refers to forms at the edges of numbered tiles (1-2 or 8-9), waiting for the outside tile.

This is one of the most inefficient waits and representative of “bad waits” (gukei). Also called “pen3” (pen-san) or “pen7” (pen-chi).

Detailed Explanation of Penchan Machi

Types of Penchan Machi

Hand pattern	Waiting tile	Acceptance count	Name
		4 tiles	Pen3
		4 tiles	Pen7
		4 tiles	Pen3
		4 tiles	Pen7
		4 tiles	Pen3
		4 tiles	Pen7

Penchan Machi Characteristics

Feature	Detail
Acceptance count	4 tiles (minimum class)
Change possibility	Very limited
Readability	Relatively hard to read
Occurrence	Common among bad waits

Usage Examples

Real Game Situations

Example 1: Tenpai Declaration

"Tenpai on pen3... tough"
":8m::9m: pen7 wait, this is harsh"

Example 2: Riichi Judgment

"Penchan but 3 dora, so riichi"
"Cheap penchan, definitely dama"

Example 3: Hand Building Regret

"Why did I accept into penchan..."
"Keeping penchan was a mistake"

Problems with Penchan Machi

Why is Penchan the Worst?

Problem	Reason
Inefficient	Only accepts 4 tiles
Hard to change	Far from good wait
3 and 7 get used	Become part of ryanmen taatsu
Dead end	No development potential

Specific Problems

is used in , ,
is used in , ,
and are easily discarded early

Ryanmen Machi: Most efficient wait
Kanchan Machi: Middle wait, bad form
Gukei: General term for bad waits
Penchan Taatsu: , forms
Pen3/Pen7: Colloquial for penchan

Common Mistakes and Points to Note

Points Beginners Often Mistake

or are not penchan
- These are ryanmen machi
- Only and are penchan
Keeping penchan too long
- Should handle early
- Don’t drag to the end
Missing all 4 visible
- All four or already visible
- Effectively formal tenpai
Expecting change too much
- Drawing with still becomes kanchan
- Not fundamental solution

Countermeasures for Penchan Machi

Early Game: Handle Early

If :1m::2m: in starting hand
→ Discard as unnecessary early

Mid Game: Prioritize Other Waits

If you have :1m::2m: and :3p::5p:
→ Keep :3p::5p: (kanchan), discard :1m::2m:

Late Game: Situational Judgment

Situation	Judgment
High points	Take tenpai even on penchan
Cheap hand	Wait for good wait change
Point status	If necessary, even penchan

Riichi Judgment on Penchan Machi

When Riichi Has Value

Mangan or higher hand
Dealer’s consecutive wins at stake
Last round conditional battle
Many dora or yaku

When Dama is Better

About 1000 point cheap hand
Still early turns
Opponent has riichi
Defense-focused situation

Special Use of Penchan Machi

Defensive Penchan Machi

Against opponent's riichi
→ Penchan wait with safe tiles :8m::9m:

Can defend while aiming for win

Penchan in Junchan

Junchan requires :1m::2m:, :8m::9m:
→ Penchan has value

Penchan Machi Statistics

Win Rate

Ryanmen machi: About 40%
Kanchan machi: About 20%
Penchan machi: About 18%
Tanki machi: About 15%

Penchan machi is statistically one of the hardest waits to win with.

Conclusion

Penchan machi, waiting for with or with , is the most inefficient wait pattern. With few acceptance tiles and little expectation of good wait changes, beginners should be careful not to create penchan taatsu from the starting hand. However, judgment to gamble even on penchan is necessary with high points or special situations. Learn the proper relationship with penchan machi and aim for more efficient mahjong.