Simultaneous clear
Clear a row and column together
The same placement fills a shared corner, completes one row and one column, and clears both in the provisional model.
Line-clear evidence
Block Blast Combo and Line Clear Planning
A simultaneous multi-line clear is something the current board model can demonstrate. A live-game Combo multiplier or streak rule requires separate evidence.
Three engine-backed Combo decisions
Look past the clear
Avoid the early-clear trap
A tempting one-line clear cannot complete the remaining two pieces. The engine instead starts with a no-clear move and completes the whole tray.
Protect future fits
Preserve critical-shape space
Survival accepts one clear and preserves six critical-shape fits, while Balanced clears two lines but leaves five.
Try all three Combo boards in the solver
Load a page-specific board to inspect the exact current tray, edit it if needed, and run the same production solver behind every example on this page.
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
Clear a row and column together
Complete the shared corner so one placement clears a row and column together.
Complete
Avoid the early-clear trap
Compare a tempting one-line clear with the safe sequence that completes the tray.
Complete
Preserve critical-shape space
Use Survival to keep an extra difficult-shape fit instead of maximizing clears.
One placement, two completed lines
The exact fixture below leaves one shared corner open. Placing the single block at row 1, column 1 completes row 1 and column 1 on the same placement, so both clear simultaneously in the provisional model.
Original engine fixture
The exact input checked
This project-owned board and these three fixed pieces are passed to the production solver unchanged.
Piece 1single
Piece 2horizontal-2
Piece 3vertical-2
Verified simultaneous-clear move
Piece 1
Move 1: single
- Top-left
- Row 1, column 1
- Cleared rows
- R1
- Cleared columns
- C1
Plan opportunities, not an invented multiplier
Consecutive line-clear opportunities can still be useful when comparing legal sequences. The solver counts cleared rows and columns and shows each resulting board; it does not convert those facts into unverified live-game points.
Simultaneous and consecutive clears are different
A simultaneous clear completes more than one row or column with the same placement, as the verified single-block example does. Consecutive clears happen on separate placements. The solver records exactly which lines clear after each move, but it does not assume that either pattern earns a particular live-game Combo value.
Why an immediate clear can be unsafe
On the trap fixture, placing the corner piece at row 4, column 5 clears one line immediately, but exhaustive search cannot place both remaining pieces afterward. The production solver recommends the vertical three-cell piece at row 4, column 3 first; that move clears no line yet keeps a complete three-piece sequence available.
Tempting one-line clear
Piece 1
Move 1: corner-top-right
- Top-left
- Row 4, column 5
- Cleared rows
- None
- Cleared columns
- C6
Safe complete sequence
Piece 3
Move 1: vertical-3
- Top-left
- Row 4, column 3
- Cleared rows
- None
- Cleared columns
- None
Piece 1
Move 2: corner-top-right
- Top-left
- Row 4, column 5
- Cleared rows
- R5
- Cleared columns
- C6
Piece 2
Move 3: square-3
- Top-left
- Row 5, column 6
- Cleared rows
- None
- Cleared columns
- None
When to trade a clear for space
The preserve-space fixture exposes the practical trade-off. Balanced clears two lines and leaves five critical-shape fits. Survival accepts one line clear and preserves six critical-shape fits. That extra difficult-shape placement can matter more than chasing the larger immediate clear when the tray is tight.
Production solver result
Balanced
Moves placed3
Lines cleared2
Empty cells38
Largest region31
Small regions2
Critical fits5
Balanced move sequence
Piece 2
Move 1: vertical-5
- Top-left
- Row 4, column 6
- Cleared rows
- None
- Cleared columns
- C6
Piece 1
Move 2: square-2
- Top-left
- Row 4, column 6
- Cleared rows
- None
- Cleared columns
- None
Piece 3
Move 3: rectangle-2x3
- Top-left
- Row 4, column 1
- Cleared rows
- R4
- Cleared columns
- None
Production solver result
Survival
Moves placed3
Lines cleared1
Empty cells30
Largest region22
Small regions3
Critical fits6
Survival move sequence
Piece 1
Move 1: square-2
- Top-left
- Row 2, column 2
- Cleared rows
- None
- Cleared columns
- None
Piece 2
Move 2: vertical-5
- Top-left
- Row 4, column 6
- Cleared rows
- None
- Cleared columns
- C6
Piece 3
Move 3: rectangle-2x3
- Top-left
- Row 4, column 1
- Cleared rows
- None
- Cleared columns
- None
A current-tray decision check
- Confirm that all three current pieces still have a legal path after the proposed clear.
- Compare the cleared lines with the connected space and difficult-shape fits left behind.
- Prefer survival when an extra clear closes the only large or long opening.
- Prefer the clear when it also opens usable space for the remaining tray.
Evidence boundary
The official Combo multiplier, streak continuation or reset timing, and platform or version differences are not implemented. The examples cover simultaneous row-and-column clearing and a deterministic line-clear-versus-space comparison under provisional-classic-v1.