Level 231 solution

Solver-verified route

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

Part of the "Seven lines" chapter. The solver certified 1000+ solving lines with 86% of in-between placements being dead ends, for a difficulty score of 15.6 (grade 2 of 5).