Strategy: solving a whole board

Techniques crack squares; strategy cracks boards. This is the end-to-end method — how to look at a fresh board, choose an order, and keep your head when a plan collapses.

Read before you draw

Give every board ten seconds of pure looking. Three questions:

• Where are the corners' owners? Each corner will be covered by somebody — usually there's only one plausible candidate.
• Which pair is the sponge? The pair whose dots are far apart, or whose region nothing else can reach, will own the biggest sweep. Identify it early; everything else routes around it.
• Where's the congestion? A cluster of dots creates walls (pipes can't cross dots) and narrow passages. Congested zones are usually forced — free deductions.

The attack order

1 Forced first. Corners, corridors, border runs — anything with exactly one possibility. These never need revisiting.

2 Short and safe second. Pairs whose route is short and hugs walls or drawn pipes. They shrink the open area without dividing it.

3 The sponge last. Route the big sweeping pipe once the remaining empty region is exactly the territory it must absorb. Drawing the sponge early is the classic over-commitment — its exact wiggle depends on everything else.

Commit vs. sketch

Draw committed pipes for forced moves and sketches for hypotheses — the game doesn't distinguish, but you should. A good sketch is a question: "if red sweeps this pocket, does everything else still fit?" Run the pocket counts on the remainder; the answer is usually immediate. Cutting a sketch costs nothing. The players who solve experts fastest are the ones who sketch most cheerfully.

When it all goes wrong

You've connected every pair and two squares sit empty, mocking you. Don't clear the board. Instead:

• Find the neighbour. Which pipes border the empty squares? One of them must detour to absorb them.
• Lengthen locally. Cut that pipe near the gap and re-route it through the empty squares. Often a two-square wiggle fixes it — and if the wiggle steals squares another pipe needed, that pipe becomes the next to adjust. Fix ripples outward, not from scratch.
• Recognize the parity trap. If a lone empty square is enclosed such that any pipe entering must also leave (no dot inside), no wiggle will ever fill it alone — a bigger reroute upstream is needed. Spotting this early saves minutes.

The clock, if you care

For leaderboard runs: deduction beats speed until the board is decided, then speed is everything. Do your reading up front, draw forced material fast and confidently, and save the sponge for one clean final sweep. A hint costs ten seconds — on a daily you're racing, that's usually more expensive than thirty seconds of honest pocket-counting.

Size changes the balance of all this — see how each board size plays.