Color Block Jam Levels 900+: A Constraint-First Method

What does constraint-first mean?

It means you begin with the route that has the fewest viable alternatives, not the block that is easiest to move. This prevents flexible space from being consumed before the critical dependency is resolved.

How should you treat a reversible move?

Prefer it when the board is ambiguous. A reversible move can reveal information without committing the last useful lane. Keep a checkpoint before any move that changes several routes at once.

What is the advanced-board habit?

After every key, chain, gate, or major blocker transition, rebuild the next dependency. Old plans are hypotheses; the changed board is the evidence.