Level 252 solution

Solver-verified route

1. Place Piece 1 across column 6 row 5, column 6 row 6.
2. Place Piece 2 across column 5 row 6, column 5 row 7, column 6 row 7, column 6 row 8.
3. Place Piece 6 across column 7 row 6, column 7 row 7, column 8 row 7, column 8 row 8.
4. Place Piece 3 across column 3 row 1, column 4 row 1.
5. Place Piece 7 across column 2 row 3, column 3 row 3.
6. Place Piece 4 across column 5 row 4, column 6 row 4, column 7 row 4, column 7 row 5.
7. Place Piece 5 across column 3 row 2, column 4 row 2, column 4 row 3.

Part of the "Master columns" chapter. The solver certified 1000+ solving lines with 82% of in-between placements being dead ends, for a difficulty score of 18.2 (grade 4 of 5).