Today the only way to stay alive in the battle is to have a lot of strength, melee/unarmed and a very good armor. I think there's a lot of other ways to stay alive irl. One of them is to stay hidden.
Let us assume a1 and s1 are your agility and stealth, a2 and s2 are your opponent's agility and stealth.
k=sqrt(abs(a1*s1-a2*s2)).
The one with small agility*stealth won't be able to target the other if he is more than 500/k tiles away. Also if one gets 500/k tiles away and he didn't initiate the battle, it (the battle) will end immediately and so the one will be able to escape. That will make an alternative way of staying alive.

P.S. Values are approximate and again sorry for my English.