A Medium 7×7 Puzzle Solved with Shape Squeeze in 14 Steps

This 7×7 board rates as medium (difficulty score 815). Solving it from scratch takes 14 logical steps, using 5 techniques: Single cell, Row/column exclusion, Adjacency clear, Region confinement, Shape squeeze. Every step below is forced: nothing here is a guess.

1. First, 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.
2. Next, 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.
3. Then, 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.
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, every remaining candidate in this region touches E3 and G3 and E4, so whichever candidate ends up marked will clear them, and they can be ruled out now regardless of which one wins.
6. From there, 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 3 touching neighbours.
7. Following that, place a marker at F3. Region has exactly one open cell left. Placing here clears the rest of row 3, column F, and its region. Placing here also clears its 1 touching neighbour.
8. First, 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.
9. Next, place a marker at D2. Region has exactly one open cell left. Placing here clears the rest of row 2, column D, and its region.
10. Then, every open cell left in this region sits in row 7, so its marker has to land there; that clears every other open cell in the row.
11. After that, every remaining candidate in this region touches B7, so whichever candidate ends up marked will clear it, and it can be ruled out now regardless of which one wins.
12. Now, place a marker at C7. Region has exactly one open cell left. Placing here clears the rest of row 7, column C, and its region. Placing here also clears its 1 touching neighbour.
13. From there, place a marker at A6. Region has exactly one open cell left. Placing here clears the rest of row 6, column A, and its region.
14. Finally, place a marker at B4. Region has exactly one open cell left.

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