Red (first player) wins with perfect play, and only by starting in the center column. Starting adjacent to center draws; anything else loses. Take Red when you can, take the center, never give it back.
A threat is an empty square completing your four. As the board fills in a zugzwang endgame, Red claims odd rows (1,3,5) and Yellow even rows (2,4,6). A threat on its useful parity is a long-term winning asset; off-parity is usually only tactical. The overlay shows exactly this: collect solid rings.
Watch the verdict box. By moves 12–16 the solver usually proves an exact result. Proven winning: the win exists — find it, and the box tracks how long you have held it. Proven lost: minimax "longest defense" is the wrong goal against a human — switch to practical chances (below).
When you are lost or drawn, the purple practical chances box ranks your moves by how few of the opponent's replies keep their result. "2/7 replies win" means five natural-looking moves throw the game away. Perfect engines never think this way; humans lose won games constantly. Set the trap with the fewest exits.
Humans deviate from theory by move 2–4, and every deviation loses — if you know the refutation. Play Red vs the Human-like opponent repeatedly: it samples plausible imperfect moves, so you rehearse the tree real people actually wander into. The grader flags you the instant a move of yours drops the forced win.