Step 1 of 5

Big patches first

The biggest patch has the fewest places to go — so start there.

The rule of thumb: Large numbers need lots of clear room, so they have the fewest places to go.

A big number needs a lot of clear space: that many cells, in one rectangle, with no other clue inside it. On a crowded board there are rarely many blocks like that, so the biggest clues are the most constrained ones on the board. Small clues are the opposite — a 2 or a 3 usually has several places to go until late.

These practice boards are picked so the habit pays off immediately: on every one, the biggest clue has exactly one fit — the only clue on the board with a single fit at the start — while at least three other clues still have three or more ways to go. Place the giant first and it boxes in everything around it; the board you’re left with is smaller in every direction.

Where to look: The largest number on the board. List the shapes it could be (a 6 is 1×6, 2×3, 3×2 or 6×1), and cross off the ones that run off the edge, break its badge or swallow another clue.

Worked example

A real position from a board built around Big patches first. Purple: what the reasoning rests on. Dashed: the patch in question. Green: what it proves.

The clue at row 5, column 5 (purple) is an 8 — the biggest on the board, and the only clue with a single fit. The dashed patch is that fit: every other way of drawing 8 cells runs off the edge, breaks its badge or swallows another clue.

Down it goes, while 3 other clues still had three or more ways to go. A patch that size boxes in everything around it — the rest of the board just got smaller.

Practice it ↓