Renju VCF #4996347 (3-move VCF)
To move: Black — find the move that forces a win by fours
Winning line
F6 → F5 → E7 → H4
Why this move works
The answer is F6. The four forces White to block at F5.
Then E7 makes two winning points at once; White cannot cover both, and H4 completes five.