Why is the uncovered center of the Bridge base blocked at the start?

The center base tiles have no tile above them, but each still has neighbors on both its left and right within a continuous 12-tile row. They fail the open-side rule, while the base tiles at both ends are covered by the raised blocks.

Must the two Bridge end blocks be cleared in lockstep?

No fixed sequence is required because the assigned faces determine which pairs exist. Inspect both blocks and preserve free ends on each; the structural priority is to create base access without assuming one exact move is always best.

Bridge Mahjong Solitaire — 72-Tile Split-Tower Board

2 layers · 12×4 tile footprint · 16 tiles initially free

Coordinate-checked board

Bridge at a glance

Difficulty: Moderate
Stack: 2 layers
Opening access: 16 of 72 tiles free

Opening priority

Scan the left and right ends of every raised 3-tile row—16 free tiles across the two end blocks. The base contributes zero free tiles initially, so begin with available matches on those upper row ends rather than the center span.

The matching and free-tile rules are shared across layouts. See How to Play for the general rules.

The span is not the opening

Bridge starts with 48 tiles in a continuous 12×4 base. Two 3×4 blocks add 12 tiles at each end on the second layer. Those raised blocks cover the outer six positions in every base row, while the six uncovered center positions remain enclosed by left and right neighbors.

As a result, every one of the 16 initially free tiles belongs to a raised block. Each of the eight upper rows contributes two ends. Base access begins only after upper removals eliminate cover and row removals create an open side.

Split-board mistakes

Trying to select an uncovered center base tile that is still blocked on both sides.
Looking at only one raised block when matching ends are available on the opposite block.
Assuming one removed upper tile automatically frees the base tile directly below it.

Bridge Mahjong Solitaire