32 · Chow patterns
Conditions
Four chows in one suit whose starting ranks consistently increase by one or by two. Short Straight or Two Terminal Chows intrinsic to that structure is excluded.
How to build it
Plan the starting ranks of the required chows. Leave enough tiles for the remaining set and pair, and check which combinations share sets.
Key tile shapes
Patterns not counted together
Pure Shifted Chows · Short Straight · Two Terminal Chows