The application has three main tabs for navigation:

• How To - You are here! Learn how to use the application
• Hand Analyzer - Enter your tiles and find matching patterns
• Pattern Catalog - Browse all 2025 card patterns organized by category. Use the powerful Search feature to enter melds you have in your hand and discover which patterns you can go for!

American Mahjong uses several types of tiles.

Example Tiles

Colored borders help identify suits: Dots (blue), Bams (green), Craks (red)

In the Hand Analyzer, you'll see the Tile Catalog at the bottom of the left panel. Click on any tile to add it to your hand.

Your Tiles Section

Concealed Hand

Click tiles in the catalog below to add them. Click a tile in your hand to remove it.

• Click a tile in the catalog to add it to your hand
• Click a tile in your hand to remove it
• Maximum 14 regular tiles including Dragons, Winds, Flowers and Jokers
• Use the Clear button to remove all tiles

When you call a tile (take another player's discard), those tiles become "exposed" and visible to other players. This affects which patterns you can complete.

Called/Exposed Tiles Section

Called/Exposed Tiles (3 tiles)

These 3 Red Dragons were called from another player's discard

How to mark tiles as called:

• First, add the tiles normally to your Concealed Hand
• Then hover over the tile you wish to call and click the down arrow (↓) to move it to Called/Exposed Tiles
• To move a called tile back to Concealed, hover over it and click the up arrow (↑)

Tile Controls

Concealed Tile

×

↓

× Remove tile

↓ Move to Called

Called Tile

×

↑

× Remove tile

↑ Move to Concealed

Hover over any tile in your hand to reveal these controls

Jokers are wild tiles that can substitute for other tiles, but with important restrictions:

Joker Example

Two Jokers substitute for two 5-Bams to complete a Kong (group of 4)

Some patterns explicitly prohibit jokers:

No Jokers Pattern

Lavender background indicates tiles where jokers are NOT allowed (singles and pairs)

After adding your tiles, click the "Find Patterns" button to discover which 2025 card patterns you can complete.

• Category - Filter results by pattern category (2025, 2468, Quints, etc.)
• Max tiles away - Only show patterns you can complete within X more tiles

Each matching pattern displays as a card showing all the information you need:

• Pattern name - The tile combination needed (color-coded by suit)
• Points - How many points this pattern is worth
• Tiles away - How many more tiles you need to complete it
• "C" or Concealed badge - Must keep all tiles hidden (no calls) for bonus points
• Description - Additional details about the pattern

Example: Matching Tiles

Suppose you have this hand:

?

?

?

The pattern match card for FF 111 2222 33333 show the breakdown as:

FF 111 2222 33333

Tiles you have

Tiles you need (3 away)

You can switch between two tile display styles using the dropdown in the tile catalog:

Simple Style

3 7 5

Colored text - clean and easy to read

Classic Style

Traditional mahjong tile images

Your style preference is saved and will persist across sessions.

The Pattern Catalog tab lets you browse all 2025 NMJL card patterns organized by category. It features a powerful Search engine that helps you find patterns based on the melds in your hand!

Toggle Options

• Show Concealed - When enabled (default), displays concealed-only patterns. Turn this off if you have already called tiles and want to hide patterns you can no longer play.
• Show Suit Variants - When enabled, expands each pattern to show all possible suit color combinations. For example, a "3 suits" pattern will display separate variants for Bams/Craks/Dots, Bams/Dots/Craks, etc. This helps you see exactly which suit arrangement matches your hand.