Medium Train Tracks Puzzles

Longer routes on an 8×8 grid

Medium puzzles double the area of the easy grids. The route typically covers 25 to 35 squares and bends many times, so you will be juggling several short pieces of track at once and joining them up as the counts allow.

Our grader allows one extra technique at this level, although only a few medium grids need it: the crossing-parity rule. Draw an imaginary line between two rows. If A and B are on opposite sides of it, the track crosses that line an odd number of times; if they are on the same side, it crosses an even number of times. On those grids it is the fact that unlocks the next move.

Habits that help at this size

Keep a running tally on each line: how many track squares are already fixed, and how many unknown squares could still take track. When those two numbers add up to the clue, every unknown square is track; when the fixed squares already meet the clue, the rest of the line is empty.

Mark empty squares with an X as soon as you know them. On an 8×8 grid a single X often turns a neighbouring square into a dead end, which forces its track to go the other way.

Where next

Medium puzzles make up the daily puzzle from Wednesday to Friday. When they start to feel routine, the hard 10×10 grids ask for longer chains of reasoning, and the strategy guide explains the extra techniques.