Shisen-Sho

What is Shisen-Sho?

Shisen-Sho, or ‘Four Rivers’ in English, is a Mahjong tile-based game originating from Japan. Japan’s TAMTEX simplified the Solitaire Mahjong concept in 1989 and brought it to arcade cabinets across the whole country. The game was a hit, finding an audience across every age group. Similar games were subsequently released and soon, Shisen-Sho became known worldwide.

How to play Shisen-Sho?

Shisen-Sho is a single-player game, and all you need to play is a Mahjong set.

For those unfamiliar, a Mahjong set has a total of 144 tiles, which are then split into 7 suits. The suits are as follows:

Suit	Tile Count
Dots (筒子)	36
Bamboo (索子)	36
Characters (萬子)	36
Winds (風牌)	16
Dragons (箭牌)	12
Seasons (季牌)	4
Flowers (花牌)	4
Total	144

Except for tiles from the ‘Flowers’ and ‘Seasons’ set, all Mahjong tiles have a duplicate, which is integral to the gameplay of the classic Mahjong.

Shisen-Sho, at its core, is a game of match-two. If you’ve played any Mahjong Solitaire games, you’ll feel right at home with Shisen-Sho. The most basic layout used in Shisen-Sho is the 18×8 rectangle.

Unlike other variants of Solitaire Mahjong, there is no vertical stacking of tiles, such as in the popular ‘Shanghai’ game, and all tiles exist on a single layer.

Shisen-Sho’s simplicity is part of the magic. By removing tiles pair-by-pair, the goal of the game is to clear the board of all tiles.

The challenge comes from the rules of tile matching. You can’t just choose any two matching tiles from across the board. Instead, the tiles need to be connected via a path consisting of not more than 2 bends. The connecting lines can only be drawn vertically and horizontally, diagonal lines are not allowed.

Rules for Shisen-Sho

Shisen-Sho starts off with the standard 18×8 rectangular layout. The Shisen-Sho rules simply state that any two matching tiles must be connected by not more than three lines. An easy way of identifying which tiles can be selected is by visualizing a single U-shape between the tiles. Once all tiles are removed, the game is considered ‘won’.

Due to the random nature of the starting board, not all configurations can be solved. The game ends once no more legal matches are possible. Experienced players will tell you that the first few matches are the most important. It’s worth knowing that certain tiles in the Mahjong set have multiple duplicates, with some having a total of 4 copies per set. Matching the wrong pair might render the board unsolvable.

In summary, the Shisen-Sho rules are:

• Set up the board in an 18×8 rectangle with all tiles from a Mahjong set.
• Match pairs of matching tiles that can be connected using a maximum of three vertical or horizontal lines.
• The game ends once no more moves are possible.

Match pairs of matching tiles that can be connected using a maximum of three vertical or horizontal lines.

Boardstates and Plays

Since Shisen-Sho uses all 144 tiles from the Mahjong set, there are nearly infinite possible starting boards. Here’s a quick introduction to possible plays you can make given a basic starting board.

Figure 1 shows the typical starting board of 144 tiles. To start things off, try looking for the same tiles lying on the same horizontal or vertical axes. At the center of the board, there is a pair of matching tiles.

This is a perfectly valid play, though the common strategy is to work starting with the outer edges. So instead, we opt for these two tiles on the far-right edge.

Note that both plays are perfectly valid. The latter play is just a more optimized variant, since it is easier to limit your vision to the outer edges to begin with.

Note that you cannot simply match two matching tiles. For example, the two inverse “中” tiles on the upper edge can be matched, as shown below.

However, the following match is illegal:

This is because there are tiles blocking the connector line.

Similarly, the following match is illegal:

You can count a total of 4 lines used in the connector, which exceeds the maximum limit of 3 lines.

Scoring

Shisen-Sho scoring is done in more competitive settings. The classic arcade machines had a timer, which would post the quickest times on the high-score list. Even now, Shisen-Sho simulator programs rank players based on their time taken.

It should be noted that not every Shisen-Sho board is solvable, but a few wrong moves can cause certain setups to reach a fail state, being unsolvable. Be sure to plan out your moves carefully, as an unsolved Shisen-Sho game is a lost game.

Strategy Tips

When it comes to Shisen-Sho strategy, the first few moves are arguably the most important. Instead of removing any matching and legal pairs right off the bat, try clearing out the outer edges as much as possible. This opens more possibilities without ruining the board state.

Most experienced players will tell you that it’s often best to avoid breaking the single rectangle into multiple shapes. Once you get a disconnected board, matches will be harder to make due to the need for more complex paths.

How to win?

With that said, the key to winning is to think out your moves. With experience, you’ll be able to intuitively figure out ideal moves.

Frequently Asked Questions

I don’t have a Mahjong set; can I still play?

You can play Shisen-Sho using any of the free simulator programs. These games are available on nearly every platform and can even be played on mobile. The benefit of using simulators is that you have access to helpful functions like the ability to undo and hints.

Are all Shisen-Sho boards solvable?

Not necessarily. However, most available Shisen-Sho simulator programs have the option to generate only solvable games. Just remember that a few wrong moves can still cause the board to fail, so be careful while making matches.

Are there alternate layouts in this game?

There certainly are, however, the classic 18×8 rectangle remains the most played due to its simplicity and symmetric nature. Much like other Solitaire Mahjong game types, feel free to experiment with layouts.

Are there different possible play modes?

If Mahjong’s traditional tile sets aren’t your jam, there are alternate versions of Shisen-Sho that might take your fancy. Back in the boom of Shisen-Sho popularity, many franchises managed to cash in on the craze by swapping out Mahjong tiles with different images. Since the rules aren’t reliant on the Mahjong tiles, everything goes.

Also read

• How to Play Japanese Mahjong
• Pinoy Mahjong