The task
- To move
- Light
- Difficulty
- Medium
- Goal
- take 10 of 16 boxes
16 boxes are still unclaimed. The best line gives the side to move a margin of 4. A 4 × 4 board in the chain phase. Count chains before you draw anything.
What to look for
- A sacrifice: giving material first is the only way to force the result.
- 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 d1-d2. The main line runs: d1-d2 · c1-d1 · d2-e2 · a2-b2 · b2-c2 · b1-b2 · b2-b3 · c3-d3 · d2-d3 · d3-e3 · d4-e4 · c3-c4 · b3-b4 · a4-b4 · b4-b5 · c4-c5 · d4-d5.