A Medium 8×8 Puzzle Solved with Shape Squeeze in 15 Steps

This 8×8 board rates as medium (difficulty score 812). Solving it from scratch takes 15 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 G, so its marker has to land there; that clears every other open cell in the column.
2. Next, 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.
3. Then, 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.
4. After that, place a marker at E5. Region has exactly one open cell left. Placing here clears the rest of row 5, column E, and its region. Placing here also clears its 2 touching neighbours.
5. Now, every open cell left in this region sits in column A, 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 H1 and H2, 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 B3 and C3, so whichever candidate ends up marked will clear them, and they can be ruled out now regardless of which one wins.
8. First, together, two regions have open cells only in rows 1 and 2; 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.
9. Next, every open cell left in this region sits in row 4, so its marker has to land there; that clears every other open cell in the row.
10. Then, place a marker at H3. Region has exactly one open cell left. Placing here clears the rest of row 3, column H, and its region. Placing here also clears its 1 touching neighbour.
11. After that, place a marker at G1. Region has exactly one open cell left. Placing here clears the rest of row 1, column G, and its region.
12. Now, 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.
13. From there, place a marker at B4. Region has exactly one open cell left. Placing here clears the rest of row 4, column B, and its region.
14. Following that, place a marker at D7. Region has exactly one open cell left. Placing here clears the rest of row 7, column D, and its region.
15. Finally, place a marker at A6. Region has exactly one open cell left.

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