In the incident I was referring to, the only person seriously injured was the one guy who fought back. I'm not saying that he wasn't right to defend himself, but he basically escalated a robbery into a four on one fight that he wasn't able to win. The assailants' motives were clear according to the article and the statements of the victims, as the assailants demanded the victims' wallets after the initial attack. I only posted this to illustrate that just going straight into combat mode might not be in your best interests. Would you rather run like hell and lose your bike, or be hospitalized/killed and lose your bike?

If someone is obviously out to hurt you, then fight away. Like you said, you've got nothing to lose if the attacker's intent is just to cause damage. That's why I said apparent motives, i.e.- motives you can decipher. If you can't figure out what they want, your responses will vary according to how the situation plays out. Maybe I'm a coward, but if I'm facing a group of young men and I've a decent exit, then I'm running. I can run a 16 minute 3k, without a potential asskicking behind me. I imagine I'd could do better with a good burst of fear adrenaline. If I end up surrounded, I'll see if I can remember anything from those Aikido classes I took 5 years ago.