Look, two blogs in 2 days! Here's my reason for making this blog (which is gonna be pretty short)-
I was curious about the connection between Chinjao and Garp. Obviously, Chinjao was a pirate. Obviously, he and Garp met at some point in their younger years. Obviously, Garp almost killed him. Obviously, Chinjao is still pretty miffed, and is willing to take it out on Luffy. My only curiousity is his true motive.
Looking at this guy, he looks anything but violent or even vengeful, but according to him and his history, he is. Being able to recognize Luffy without so much as a second glance, he's either seen his wanted poster plenty of times before, or he can recognize a descendant of Garp in an instant. So, he's recognized Luffy, what's he gonna do about it?
Well, my guess is he's not really out for revenge. Sure, he's not happy about his almost-death, but I doubt he's really looking for blood. I think he'll really enjoy beating Luffy around a bit, maybe see some fear in his eyes, but after Luffy really puts up a fight and Chinjao says something like "You really are your grandfather" or something, he'll back off.
Long story short, I think Chin's just testing Luffy's abilities all while beating him up a little.