Level 221 solution

Solver-verified route

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

Part of the "Final columns" chapter. The solver certified 720 solving lines with 93% of in-between placements being dead ends, for a difficulty score of 17.6 (grade 3 of 5).