The task
- To move
- Dark
- Difficulty
- Easy
- Goal
- take 7 of 9 boxes
9 boxes are still unclaimed. The best line gives the side to move a margin of 5. A small board near the end. Decide whether to take or to decline.
What to look for
- Decline the last two boxes of a chain to keep control.
- Control: make your opponent open the long chains.
How the answer is checked
There is exactly one first move that forces the result; any other first move allows the defence to escape. Moves that keep the forced result are accepted later in the line, and a move that loses it is taken back with a short note.
Show the key move
The key move is a1-a2. The main line runs: a1-a2 · a2-b2 · b2-c2 · c1-c2 · d1-d2 · c2-c3 · c3-d3 · c3-c4 · b3-b4 · a4-b4.