A Medium 7×7 Puzzle Solved with Shape Squeeze in 13 Steps

This 7×7 board rates as medium (difficulty score 794). Solving it from scratch takes 13 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 A, so its marker has to land there; that clears every other open cell in the column.
2. Next, 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. Placing here also clears its 2 touching neighbours.
3. Then, together, two regions have open cells only in columns C and D; 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.
4. After that, together, two regions have open cells only in rows 6 and 7; 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.
5. Now, every open cell left in this region sits in column E, so its marker has to land there; that clears every other open cell in the column.
6. From there, 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.
7. Following that, every remaining candidate in this region touches G2 and E3 and G3, so whichever candidate ends up marked will clear them, and they can be ruled out now regardless of which one wins.
8. First, 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.
9. Next, 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. Placing here also clears its 1 touching neighbour.
10. 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.
11. After that, place a marker at F3. Region has exactly one open cell left.
12. Now, 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.
13. 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. ∎