A Steady 8×8 Puzzle Solved with Shape Squeeze in 17 Steps

This 8×8 board rates as steady (difficulty score 848). Solving it from scratch takes 17 logical steps, using 6 techniques: Single cell, Row/column exclusion, Adjacency clear, Region confinement, Paired regions, Shape squeeze. Every step below is forced: nothing here is a guess.

1. First, every open cell left in this region sits in column H, so its marker has to land there; that clears every other open cell in the column.
2. Next, together, two regions have open cells only in columns A and B; with one marker each, those two markers have to fill exactly those two columns, so every other region's open cells there can be cleared.
3. Then, place a marker at C2. Region has exactly one open cell left. Placing here clears the rest of row 2, column C, and its region. Placing here also clears its 2 touching neighbours.
4. After that, place a marker at H1. Region has exactly one open cell left. Placing here clears the rest of row 1, column H, and its region.
5. Now, every open cell left in this region sits in column D, so its marker has to land there; that clears every other open cell in the column.
6. From there, every remaining candidate in this region touches F3 and F4, so whichever candidate ends up marked will clear them, and they can be ruled out now regardless of which one wins.
7. Following that, every remaining candidate in this region touches E4 and E5, so whichever candidate ends up marked will clear them, and they can be ruled out now regardless of which one wins.
8. First, every open cell left in this region sits in row 3, so its marker has to land there; that clears every other open cell in the row.
9. Next, together, two regions have open cells only in rows 4 and 5; with one marker each, those two markers have to fill exactly those two rows, so every other region's open cells there can be cleared.
10. Then, every open cell left in this region sits in column G, so its marker has to land there; that clears every other open cell in the column.
11. After that, place a marker at E3. Region has exactly one open cell left. Placing here clears the rest of row 3, column E, and its region. Placing here also clears its 1 touching neighbour.
12. Now, place a marker at D5. Region has exactly one open cell left. Placing here clears the rest of row 5, column D, and its region.
13. From there, place a marker at A4. Region has exactly one open cell left. Placing here clears the rest of row 4, column A, and its region.
14. Following that, every remaining candidate in this region touches F6 and F7, so whichever candidate ends up marked will clear them, and they can be ruled out now regardless of which one wins.
15. First, place a marker at F8. Region has exactly one open cell left. Placing here clears the rest of row 8, column F, and its region. Placing here also clears its 1 touching neighbour.
16. Next, place a marker at G6. Region has exactly one open cell left.
17. Finally, place a marker at B7. Region has exactly one open cell left.

The key move here was Shape squeeze. Once you can spot that, this board falls quickly. ∎