How to solve this 8×8 logic puzzle

8×8 · steady · 10 steps

This 8×8 board rates as steady (difficulty score 748). Solving it from scratch takes 20 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.

First, place a marker at row 1, column 8. Region has exactly one open cell left. Placing here clears the rest of row 1, column 8, and its region. Placing here also clears its 1 touching neighbour.
Next, place a marker at row 2, column 3. Region has exactly one open cell left. Placing here clears the rest of row 2, column 3, and its region. Placing here also clears its 2 touching neighbours.
Then, place a marker at row 3, column 7. Region has exactly one open cell left. Placing here clears the rest of row 3, column 7, and its region. Placing here also clears its 1 touching neighbour.
After that, place a marker at row 5, column 6. Region has exactly one open cell left. Placing here clears the rest of row 5, column 6, and its region. Placing here also clears its 2 touching neighbours.
Now, place a marker at row 4, column 2. Region has exactly one open cell left. Placing here clears the rest of row 4, column 2, and its region.
From there, every open cell left in this region sits in row 8, so its marker has to land there — clearing every other open cell in the row.
Following that, every remaining candidate in this region touches row 7, column 4 and row 7, column 5 — so whichever candidate ends up marked will clear them, and they can be ruled out now regardless of which one wins.
First, place a marker at row 6, column 4. Region has exactly one open cell left. Placing here clears the rest of row 6, column 4, and its region.
Next, place a marker at row 7, column 1. Region has exactly one open cell left.
Finally, place a marker at row 8, column 5. Region has exactly one open cell left.

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