How the Board Health Score Works
Block Master's board health score is a 0 to 100 heuristic that summarizes measured flexibility for the current board and offered pieces. It combines move availability, open geometry, difficult-piece fit, clear potential, and isolated-hole penalties. It does not predict a guaranteed final score.
Working definition: A heuristic is a transparent decision aid that approximates a useful quality without exhaustively solving every possible future piece sequence.
The published formula
The score uses 35 times move availability, 20 times largest open rectangle, 15 times open lanes, 20 times hardest-piece fit, and 10 times clear potential, then subtracts eight for each isolated hole. The result is rounded and clamped between zero and one hundred.
Most components are ratios against the same offered pieces on an empty board. This keeps a naturally restrictive long bar from being compared directly with a single cell. The hardest-piece term uses the lowest fit ratio in the tray.
Read components, not only the total
A score of 72 labeled Open can hide one weak component. If hardest-piece fit is near zero, inspect that piece before trusting the overall number. Strong open lanes and a large rectangle may still provide an enabling clear, but the risk is immediate.
A Critical board is not necessarily lost. One multi-clear can transform the geometry. The score updates after every simulation so you can compare the measured result instead of assuming that a crowded board cannot recover.
Where the metric can mislead
The heuristic does not search arbitrary future piece sequences and does not attach human strategic value to a specific setup beyond its components. It may prefer broad space over a narrow position that guarantees a high-scoring clear with the current tray.
Use it as an explanation layer. If two moves have similar health, inspect score, piece order, and clear structure. Version one of the formula favors survival and visibility over aggressive point maximization.
Field notes and measurable checks
Move availability is normalized against an empty board for the offered set. If three pieces have 30 legal origins now and 100 in total on an empty board, the component is 0.30. This prevents a naturally flexible single cell from making a tray look healthy when the other two shapes are nearly impossible. Hardest-piece fit separately highlights the weakest member.
Largest open rectangle deliberately ignores irregular connected regions. A winding empty area may contain many cells but reject a square or bar, while a smaller rectangle accepts several shapes. Open-lane score adds another view by checking rows and columns for a run of at least five. The components overlap by design but emphasize different failure patterns.
Clear potential counts legal simulated moves that complete at least one unit. It does not value a triple clear more than a single clear inside that component, because scoring already measures reward. This separation keeps the health model focused on access to a reset. Isolated holes then apply a fixed penalty so fragmented boards do not receive an inflated score from raw emptiness.
Version one can be stress-tested with counterexamples. Construct a narrow board that guarantees a two-unit clear but has a small rectangle, then compare it with a broad board that offers no immediate score. If the broad board ranks higher, the model is behaving as a survival heuristic. The player can still select the lower-health clear when the visible tray makes its reward compelling.
A repeatable decision routine
- Read the total label and numeric value.
- Find the weakest component in the list.
- Compare candidate moves using the same offered pieces.
- Apply scoring and piece-order judgment before choosing.
Common mistakes
- Calling the top health move guaranteed optimal.
- Comparing scores calculated from different offered pieces without context.
- Ignoring a zero difficult-piece fit beneath a healthy total.
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
What do Open, Tight, and Critical mean?
Open is 70 to 100, Tight is 40 to 69, and Critical is 0 to 39.
Does higher health guarantee a better run?
No. It only indicates more flexibility under the published measurements.
Why is each hole worth minus eight?
The fixed penalty makes isolated cells visible, but it remains a heuristic design choice rather than a universal law.
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.