Renju VCF #4996509 (7-move VCF)
To move: Black — find the move that forces a win by fours
Winning line
I8 → H7 → L5 → K6 → F8 → G8 → K8 → L8 → M6 → L7 → K11 → K7
Why this move works
The answer is I8. From I8 you fire off fours that force White’s replies — a seven-move VCF (I8→H7→L5→K6→F8→G8→K8→L8→M6→L7).
The decisive K11 makes two winning points at once; White cannot stop both, and K7 completes five.