Horizontal opening
Horizontal 1×5 fits now
The only five-cell opening accepts the horizontal bar and clears the top row. The engine then completes the remaining two pieces.
Long-lane planning
Block Blast Long Block Guide
Compare horizontal and vertical five-cell lanes, then protect the only opening that matches the current fixed orientation.
Why orientation matters for a 1×5 block
A horizontal 1×5 needs five adjacent empty cells in one row. A vertical 5×1 needs five adjacent empty cells in one column. The solver keeps the entered orientation fixed, so a lane in the other direction does not count.
Three engine-backed long-block situations
Protect one corridor
Preserve the vertical 5×1 lane
The same single-cell piece has a safe placement outside the corridor and an unsafe placement inside the only vertical lane. The engine can complete the tray after the safe choice, while the unsafe choice cannot complete the remaining pieces.
No long lane
Both long bars stay blocked
Neither the horizontal 1×5 nor the vertical 5×1 has a legal first move on the checkerboard fixture, and the third entered piece is blocked too.
Try all three long-block boards in the solver
Load a page-specific board to inspect the exact fixed orientation, available lane, and recommended current-tray sequence.
Step 1
Mark the filled board cells
Click, tap, or drag to paint. Row 1 is the top row.
Step 2
Enter the three fixed pieces
Choose a preset or draw the exact orientation you see.
Current tray
Piece 1
Choose a preset
Single
Lines
Squares and rectangles
Corners
Draw a custom shape
Current tray
Piece 2
Choose a preset
Single
Lines
Squares and rectangles
Corners
Draw a custom shape
Current tray
Piece 3
Choose a preset
Single
Lines
Squares and rectangles
Corners
Draw a custom shape
Step 3
Choose a strategy and solve
Verified inputs
Try a verified example
Complete
Horizontal 1×5 fits now
Use the only five-cell opening to complete and clear the top row.
Complete
Preserve the vertical 5×1 lane
Compare safe and unsafe single-cell placements around the only vertical lane.
No first move
Both long bars stay blocked
See a crowded board where neither long orientation has a legal first move.
A practical long-block checklist
- Match the piece orientation before counting empty cells.
- Look for five uninterrupted cells in the required row or column.
- When only one matching lane remains, test every earlier move before placing an easier piece inside it.
- Use the solver to compare the full current tray instead of assuming the first legal placement is safe.
Evidence boundary
These examples evaluate only the entered current tray under provisional-classic-v1. They do not rotate pieces, predict future trays, claim an official complete shape inventory, or estimate how often a long block appears.