Loose Ends
Join the pairs. Fill the board.
Join the pairs. Fill the board.
Draw a path between each pair of matching dots. Paths cannot cross, and every square on the board has to be used.
Start at the edges and in the corners. A square in a corner has only two neighbours, so the path through it has only one way to turn, and a dot on the edge has three ways out rather than four. Then look for the pair with the fewest routes: two dots with a wall of other dots between them, or a dot boxed in on three sides. Short paths tend to run between long ones, and long ones sweep round the outside of the board, so a path that leaves a pocket of one or two squares nothing else can reach is the wrong path, however tidy it looks. Every change is a stroke, so work a route out before you draw it: an empty board costs nothing to look at.