The secret rule is this:
The secret rule contradicts sporting law, which is primacy in competition.
The secret rule prioritizes skills development and fosters the hope that—at last!—sons win! Sons beat Dad.
I modulate play to increase focus: We can win, we can win, we can win… if…
Their skills grow stronger, their play improves, their confidence grows.
That is winning.
Run. Shoot… Kick! SCORE!
They win. I win.