Rows, Columns, and 3x3 Box Clears
A full 9-cell row, a full 9-cell column, or a full outlined 3x3 box clears in Block Master. The engine detects every unit completed by one placement and removes their combined cells at the same time, so an intersection can score multiple clears.
Working definition: A completed unit contains no empty cells after the piece is placed. Overlapping cells belong to each completed unit for scoring, but each occupied cell is removed only once.
Single clears establish space
A single clear is valuable when it produces a clean region for the next tray. Finish a row from one side when possible so the cells above and below remain regular. Filling a scattered set of final gaps may score the same points but leave awkward pockets.
For a box clear, watch all nine cells rather than its perimeter. A central missing cell is easy to overlook beneath a large piece preview. The placement is valid only on empty cells, and the box clears only when all nine are occupied.
Intersections create multi-clears
Suppose row five needs one cell and column five also needs that same cell. A single-cell piece at their intersection completes two units. Under Block Master scoring, the turn earns 1 placement point, 36 clear points, a 12-point multi-clear bonus, and a streak bonus if the prior turn also cleared.
A row, column, and box can all meet on one placement. The engine records all three before clearing, so removing the row first cannot prevent the box from being recognized. This simultaneous rule makes shared intersections worth planning.
Do not force every intersection
A triple-clear setup can consume most of the board while you wait for one exact piece. If that piece is absent, the setup becomes a liability. Prefer intersections that accept several shapes or that still leave a normal single-clear route.
After a clear, evaluate the remaining shape of empty space. High points do not automatically mean high flexibility. A modest clear that protects a long lane can outlast a spectacular clear that creates isolated holes.
Field notes and measurable checks
A good clearing exercise starts with eight occupied cells in a row, eight in a column, and a shared empty intersection. Place a single cell at that intersection and record the two completed units before any removal occurs. Then repeat after breaking one distant cell in the row. The same placement now completes only the column, proving that adjacency to an intersection is not enough.
Boxes create a second kind of overlap. Place eight cells in the center 3x3 box and prepare the middle row so that the missing box cell is also its final gap. The finishing piece completes two units even though one target is local and one spans the board. After simultaneous removal, count the distinct cells cleared rather than adding nine plus nine, because shared cells disappear once.
Clear detection should never depend on animation order. Block Master evaluates the fully placed board, records every complete unit, and only then removes cells. This rule is important for reproducible scoring and for assistive status messages. A visual effect may emphasize one unit before another, but it cannot change the score, the list of completed units, or the resulting board.
A repeatable decision routine
- Locate the unit with the fewest empty cells.
- Check whether the finishing piece also completes another unit.
- Place the piece and detect all completed units together.
- Inspect the cleared board before planning the remaining tray.
Common mistakes
- Counting an outlined box as full while its center is empty.
- Forcing an intersection that depends on one exact piece.
- Judging a clear only by points instead of the resulting board.
Try the routine on the practice board, then compare your own position in the analyzer. The shared engine keeps the examples, measurements, and game rules consistent.
Questions about this strategy
Can a cell count for two clears?
Yes. It can complete more than one unit, while being removed only once.
Are boxes optional?
No. All nine outlined 3x3 boxes are active clear units in Block Master.
When are clears detected?
After the placement and before any completed cell is removed.
Next action
Open Block Master and apply this lesson to the first tray that creates the relevant pattern. Pause after the move, read the weakest health component, and decide whether the board confirms your expectation.