Bridge Mahjong

Bridge is our own layout for Mahjong solitaire: two towers, each 4 tiles wide and 8 deep, joined by a bridge two tiles wide, all two layers high. You clear it by taking the 144 tiles off two at a time, each pair the same tile, and only tiles that are free. A tile is free when nothing lies on it and its left or right side is open. Flowers pair with any flower and seasons with any season.

The tiles, the controls and Shuffle work as on the turtle; the Mahjong Solitaire page explains each tile.

Only two layers: 80 tiles on the ground and 64 on top. Each tower is a block 4 tiles wide and 8 deep, with a second layer of 4 by 6 on top. The bridge between them is two rows deep and two layers high, so its rows run 16 tiles from one tower's outer side to the other's.

Long rows open only from their two ends. That is why just 28 tiles are free at the start, the fewest of our layouts, and why the order you open the rows in matters more here than how deep a tile is buried.

• Start from the towers' outer sides: those row ends are free and lead into the long rows.
• A bridge row opens one tile at a time from each end. Count which kinds you need in the middle of the bridge and keep a free twin for each.
• The ground rows at the top and bottom edge of each tower have nothing on them. The rest of a tower is two layers deep: every top tile you take uncovers exactly one tile below.
• You often start with only 3 to 11 kinds with a free pair. Use Hint early if you are unsure; it shows a pair from a line that still clears the board.

We built 1,044 Bridge deals, each from a way to clear it. Our solver had to find its own way through each one; it cleared 1,000 within its search limit, and those are the deals you play here.

Across 300 of these deals, the first position offers on average 7.7 kinds of tile with a free pair (3 at the fewest, 11 at the most), against 10.8 on the turtle. It is the tightest start we have.