A Medium 8×8 Puzzle Solved with Shape Squeeze in 14 Steps

This 8×8 board rates as medium (difficulty score 790). Solving it from scratch takes 14 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 row 1, so its marker has to land there; that clears every other open cell in the row.
2. Next, every open cell left in this region sits in row 2, so its marker has to land there; that clears every other open cell in the row.
3. Then, together, two regions have open cells only in rows 3 and 4; 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.
4. After that, every remaining candidate in this region touches F2, so whichever candidate ends up marked will clear it, and it can be ruled out now regardless of which one wins.
5. Now, place a marker at E2. Region has exactly one open cell left. Placing here clears the rest of row 2, column E, and its region. Placing here also clears its 3 touching neighbours.
6. From there, 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.
7. Following that, 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.
8. First, place a marker at B5. Region has exactly one open cell left. Placing here clears the rest of row 5, column B, and its region. Placing here also clears its 2 touching neighbours.
9. Next, place a marker at A3. Region has exactly one open cell left. Placing here clears the rest of row 3, column A, and its region.
10. Then, place a marker at H4. Region has exactly one open cell left. Placing here clears the rest of row 4, column H, and its region.
11. After that, every open cell left in this region sits in column F, so its marker has to land there; that clears every other open cell in the column.
12. Now, place a marker at D6. Row 6 has exactly one open cell left. Placing here clears the rest of row 6, column D, and its region.
13. From there, place a marker at C8. Region has exactly one open cell left. Placing here clears the rest of row 8, column C, and its region.
14. Finally, place a marker at F7. Region has exactly one open cell left.

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