Back when I was in the navy a friend and I had to get off of the trolley in San Diego at a less than desirable location to get back to the base. We were aware of our surroundings and were on our toes. We had heard stories of other sailors being beat up and robbed in the area and it was not long before we were being shadowed. It was two guys. We had to cross a bridge to get back to the base and I told my friend we make our stand on the bridge where we could control the direction they came at us better.
I am a lot bigger than my friend and one of the attackers. My friend looked at me like I was crazy when I told him to engage the big guy. I told him my plan was simple. My friend was a black belt in T’ai Chi so I figured he should be able to hold his own for a couple of minutes while I simply grabbed the little assailant by the scruff of the neck and chucked him off the bridge. Then there would be two of us to engage the other guy.
About halfway across the bridge we turned around and spread apart a few feet making it clear by our postures we were ready to fight back. They stepped out of the shadows and sized us up and turned and went back the way they had come.
My guess is they wanted targets that would be easier to intimidate and it was clear we were ready for a fight.