I think its somewhat easy to tell when you have lost and won. When playing my rush deck, I find that clearing a field and playing safe therefore after keeps me ahead. Even if they wipe out my first two cards (Monk and Kurina) I usually still have Salamander, Magic Swordsman, gowens little archer for SP build-up. Bring out Revolver Knight or buff with dryad to keep my small units going. Even if I lose ond or two cards, my SC's are activated which further wipe out the other field. I either then heal my damaged units or if I have enough SP to spare, attack their LP.