Level 199 solution

Solver-verified route

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

Part of the "Deep board" chapter. The solver certified 720 solving lines with 94% of in-between placements being dead ends, for a difficulty score of 18.9 (grade 4 of 5).